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Postfix 2.1 Released

MasTRE writes "After an extended period of polishing and testing, Postfix 2.1 is released. Some highlights: complete documentation rewrite (long overdue!), policy delegation to external code, real-time content filtering _before_ mail is accepted (a top 10 most requested feature in previous versions), major revision of the LDAP/MySQL/PGSQL code. Version 2.2 is in thw works, which promises even more features like client rate limiting and integration of the TLS and IPv6 patches into the official tree. There's never been a better time to migrate from Sendmail (just _had_ to get that in there ;)."

96 of 286 comments (clear)

  1. Aaargghhh! by gowen · · Score: 5, Interesting

    It would be nice if, during product announcements, if the submitter actually included a sentence SAYING WHAT THE SOFTWARE DOES.

    Yes, I know its an SMTP server, but sheesh, is it so hard to start it "After an extended period of polishing and testing, Postfix, the popular open source mail transfer agent, has reached version 2.1

    --
    Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
    1. Re:Aaargghhh! by mattdm · · Score: 4, Funny

      Pssh. C'mon, what kind of geek hasn't heard of Postfix? I mean, sure, this'd be a valid complaint if we were talking about exim....

      *grin*

    2. Re:Aaargghhh! by StormyMonday · · Score: 2, Interesting

      I'll second that.

      On far too many Open Source projects, it's a real struggle to figure out what the durn thing is supposed to do. Go to the website, get a list of contributers, a changelog, and perhaps some press releases. Fire it up, click "help->about" and get a logo. Nothing says what it does.

      WHAT THE BLEEP IS IT SUPPOSED TO DO?

      --
      Welcome to the Turing Tarpit, where everything is possible but nothing interesting is easy.
    3. Re:Aaargghhh! by Billy+the+Mountain · · Score: 4, Funny

      Pssh. C'mon, what kind of geek hasn't heard of Postfix?

      I agree postfix is ubiquitous, although prefix and infix have their merits as well!

      BTM

      --
      That was the turning point of my life--I went from negative zero to positive zero.
    4. Re:Aaargghhh! by Anonymous Coward · · Score: 4, Interesting

      I never understood why computer scientists often use the word "postfix", because this is a term invented by biologists (anatomy). Linguists and mathematicians say "suffix" instead.

      I use both words, and I use them to mean different things. "Suffix" (in my idiolect) means "a bound morpheme attached to the end of a word"; "postfix" means "an unbound morpheme attached at the end of a word".

      Are you saying mathematicians really refer to the style of "2 3 +" as "suffix notation"?

    5. Re:Aaargghhh! by spektr · · Score: 3, Informative

      I use both words, and I use them to mean different things. "Suffix" (in my idiolect) means "a bound morpheme attached to the end of a word"; "postfix" means "an unbound morpheme attached at the end of a word".

      Interesting. After doing some more research, I think it's time for me to give the word "postfix" a bigger place in my heart.

      Are you saying mathematicians really refer to the style of "2 3 +" as "suffix notation"?

      No, I found this entry in the Oxford English Dictionary: "MATH. An inferior index written to the right of a symbol, a subscript".

    6. Re:Aaargghhh! by Profane+MuthaFucka · · Score: 4, Informative

      Yes, I'd recommend that you look at both. Both are excellent, but in my experience some people who can't make sense of postfix configuration find Exim to be intuitive. And vice-versa. You won't know if you are a postfix or an exim person until you look at both.

      --
      Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
    7. Re:Aaargghhh! by cos(0) · · Score: 3, Informative

      Are you saying mathematicians really refer to the style of "2 3 +" as "suffix notation"?

      No, they refer to it as Reverse Polish Notation.

  2. Why does everyone alwasy gotta knock sendmail?? by darthcamaro · · Score: 4, Interesting

    I've been running sendmail 4ever - sure it's complicated as hell - and a bit of a resource hog at times..but it freaking works and is rock solid over more years of production use than any other MTA ever will be in our lifetimes.

    1. Re:Why does everyone alwasy gotta knock sendmail?? by woulduno · · Score: 4, Insightful

      Cause Postfix was built for people who do not understand how to properly configure a mailserver. It assumes you are new and keeps it locked down by default. Where sendmail is more customizable and faster (http://www.benchmarks.dmz.ro/article.php?story=20 02081221400018), although Qmail is faster, for standard configurations.. Sendmail is great for large high volume sites, where postfix is great for the home user or smaller sites. Although it can still be used in larger sites.. I personally have been using sendmail for years and cannot remember a security issue that applied to me. Mostly because I know how to configure sendmail and it is very well tuned. I worked with a company that sent stock notifications where we pushed over 5 million messages in under 30 minutes with 8 Sun Netra's with 440 mhz CPU's.. In case you do not get the math that is about 20,833 thousand messages per minute per machine! Running sendmail..

    2. Re:Why does everyone alwasy gotta knock sendmail?? by Christianfreak · · Score: 4, Interesting

      The last study I read showed the exact opposite. With Postfix being the fastest, sendmail close behind and qmail way slower than the other two.

      Cause Postfix was built for people who do not understand how to properly configure a mailserver.

      Feeling a bit up on yourself are you? I've used all three and as a busy sysadmin I have to say I don't have time to screw around with with Sendmail security patches and overly complex setup or qmail's complete lack of flexability. I have a fairly complex Postfix setup that stores my users in Mysql, does spam and virus checking and handles about 40 domains. I set it all up in about half a day ... I don't even want to think about how long it would have taken to do it with sendmail.

    3. Re:Why does everyone alwasy gotta knock sendmail?? by ckaminski · · Score: 2, Interesting

      Right, I have time to read an 800 page configuration guide. Personally, I prefer a system that's locked down to start, is easy to get going, and is scalable. Everything that sendmail is not (or wasn't under 8.x). ;-)

      I've used sendmail, and I've used postfix. I definitely prefer postfix. I didn't think I would, I had a serious sendmail bias a few months ago, but I'm a convert. PGSQL support did it for me, I think.

  3. As my head explodes.... by lacrymology.com · · Score: 5, Funny

    Wait, wouldn't post fix Postfix 2.1 actually be fix 2.2?

    -m

    --

    #
    # Modus Ponens
    #
    1. Re:As my head explodes.... by Nahor · · Score: 2, Funny

      No, no, you don't get it, it's because of all the filters. It fixes posts. So now, pe0ple kan wreite az badi az the want & get there pausts fyxt too a corekt form@t. This is a big help for spam filtering, no more v.iagr@, v1 gra, and stuff.

      I wonder if this technology would work for /. to spelling.

  4. Already Upgraded...works great. by haplo21112 · · Score: 4, Informative

    I upgraded first thing this morning when I saw the listing on freshmeat. So far its a drop in replacement.

    Download
    tar -zxvf
    cd postfix-2.1.0
    make
    make upgrade
    postfix stop
    postfix start

    No issues what so ever!

    Even working correctly with TMDA whitelisting/blacklisting spam filter, which had been my one real concerns did anything happen that could screw up TMDA. NOPE! Runs fine.

    Have to go ahead and look into setup and using some of the new features now I suppose.

    --
    Power Corrupts,Absolute Power Corrupts Absolutely, leaving one person(group)in charge is absolutely corrupt.
  5. Re:Next time... by Anonymous Coward · · Score: 5, Funny


    Many of us are happy with Sendmail

    .. as are the kiddies that've r00ted your mail server.

  6. Comparisons by thebra · · Score: 2, Informative

    on sendmail, qmail, exim, and postfix. HERE

    1. Re:Comparisons by Ryquir · · Score: 5, Informative

      Yeah your comparisons link is seriously outdated (cicra 2001) and only compares mta descriptions. It is neither indepth nor does it touch on the features that existed at the time. With statements like "Add to this sendmail's renowned inefficiency" or "Postfix is quite flexible in its configuration file, but not to the extent of Exim" this document can't be anything more then a abstract draft written up for basic filler in attempt to sell a book idea to publishers.

      This wouldn't have been a good comparison at the time it was written let alone now. Next time try googling a little harder perhaps you would have found this link: http://www.geocities.com/mailsoftware42/ or heck google it for yourself here http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF -8&q=MTA+comparison&btnG=Google+Search

  7. Postfix performs quite well by bigberk · · Score: 4, Interesting

    I recently configured a 200 MHz Pentium host (with slow IDE drives etc.) as an ISP's mail server. It handles over 10,000 emails daily and the load average hangs around at 0.10 -- it's using Postfix with the renattach attachment filter as a content filter (catches all those windows viruses). I was pretty impressed that Postfix performed so well on such an ancient machine :)

  8. Re:versioning by gowen · · Score: 4, Informative

    That was basically Linus's idea. Some people have copied it (Gnome and Gimp hackers spring to mind), but its by no means all pervasive.

    --
    Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
  9. because it's an ugly, lumbering dinosaur by SuperBanana · · Score: 5, Interesting

    I've been running sendmail 4ever - sure it's complicated as hell - and a bit of a resource hog at times..but it freaking works and is rock solid over more years of production use than any other MTA ever will be in our lifetimes.

    On a Axil 320(110mhz, I think? I forget which sparc chip) running Solaris w/320MB of ram and one single SCSI drive, on a Mailman list with about 2,000 subscribers and 100 posts a day, we went from delivery times of an hour+(and load averages well over 4) to under 5 minutes(and load averages between .5 and 2).

    Proponents of Sendmail will say "oh, it just needs to be tuned properly".

    Nope, sorry. Proper software doesn't need tuning to do its job. Ever notice that the only proponents of the "it just needs someone who knows how to tune it" model are...well...the limited number of people who know how to tune it, and are fast finding themselves out of jobs?

    1. Re:because it's an ugly, lumbering dinosaur by darthcamaro · · Score: 2, Interesting

      Under 5 minutes? that's sweet - you did this with Postfix? and how did you manage the MTA change in all your apps or did you only have to do in GNU/Mailman?

    2. Re:because it's an ugly, lumbering dinosaur by beegle · · Score: 4, Informative

      Postfix has a sendmail-compatable setup where it creates a binary named "sendmail" that accepts common sendmail flags. In most setups, a switch-over is totally transparent.

      The hardest part is deciding which of your Sendmail optimizations are still necessary on Postfix.

      Sendmail is mostly around because of inertia. It can also do a few sick things (like bridging SNMP and non-SNMP mail systems) that are not necessary for most sane people.

      --
      --
    3. Re:because it's an ugly, lumbering dinosaur by beegle · · Score: 4, Funny

      Sigh. s/SNMP/SMTP/g

      If an SNMP-based mail system exists, I don't want to know about it. :-)

      --
      --
    4. Re:because it's an ugly, lumbering dinosaur by Just+Some+Guy · · Score: 5, Insightful
      Proper software doesn't need tuning to do its job.

      You may or may not be correct in this particular case, but as a general statement, that's just stupid.

      Do you really mean that the exact same settings for a little desktop (high priority to input-related tasks, swap only when needed) would work well for a high-load server (high priority to compute-related tasks, swap agressively to make RAM quickly available)? There are a lot of settings on a modern system that just can't be inferred by the system itself. Stating the opposite like it's an obvious fact is ignorant, misleading, or both.

      A real-world example: a Usenet spool and an MP3 repository may be the same size, but benefit hugely from tweaked bytes-per-inode or journal settings. In some cases, once the system is running, it's too late to easily change your mind (like bytes-per-inode). In other cases, you can switch at will, but not without unmounting the filesystem (ext3 journaling options). You, as the administrator, make those decisions. Either way, even if the computer were capable of recognizing that you'd made a bad decision, it's not in a position to correct them.

      A real-world example: I tuned Sendmail to use delayed sending so that when a client blasted 20,000 copies of a newsletter (yes, opt-in), then it would wait for several minutes so that it could efficiently aggregate recipients by domain. In there situation, telling Sendmail to leave email in the queue for 10 minutes meant a 50% savings in bandwidth. How on earth would you expect a self-tuned MTA to ever make that discovery on its own?

      Computers do some things well. Predicting the future usage patterns of their owners without mounds of previous input is not one of them. That's where manual tuning comes in, and why real system administrators still paid decently.

      --
      Dewey, what part of this looks like authorities should be involved?
    5. Re:because it's an ugly, lumbering dinosaur by mattdm · · Score: 2, Informative

      and how did you manage the MTA change in all your apps or did you only have to do in GNU/Mailman?

      On fedora: run 'system-switch-mail', pick postfix, hit okay, you're done.

    6. Re:because it's an ugly, lumbering dinosaur by iainf · · Score: 2, Informative

      how did you manage the MTA change in all your apps

      Postfix presents itself as sendmail; it just drops in as a direct replacement. From my Mandrake box:

      % file `which sendmail` /usr/sbin/sendmail: symbolic link to `/etc/alternatives/mta'
      % file /etc/alternatives/mta /etc/alternatives/mta: symbolic link to `/usr/sbin/sendmail.postfix'

    7. Re:because it's an ugly, lumbering dinosaur by Martin+Blank · · Score: 2, Funny

      I sense a new project coming on SourceForge... :)

      --
      You can never go home again... but I guess you can shop there.
    8. Re:because it's an ugly, lumbering dinosaur by ckaminski · · Score: 2, Informative

      He meant for clients, not server config. The typical:

      system("/usr/bin/sendmail -m user@host.tld");

      Is unchanged when migrating to postfix. The backend, however, has some extremely significant differences.

      You weren't trolled, you just didn't understand his argument correctly.

  10. to update or not to update? by Chuck+Bucket · · Score: 2, Interesting

    that's the question.

    I've been running Postfix for 8 months now, and I much, much prefer it to my life of running Sendmail for the previous 2 years. Anyway, I've been running Postfix, it has worked perfectly for me, and my 8 other mail users, and I have kept up to date on all/any security patches. Is there any compelling reason for me to upgrade? If the newer one is faster, more effiecent, that's great, but for a small server like mine I'm not sure if I'm even going to notice.

    Anyone with helpful advice is appreciated. TIA.

    VSCB

    1. Re:to update or not to update? by arcanumas · · Score: 5, Funny
      dude, with 8 users you could use trained pigeons and not see a difference.

      --
      Slashdot Sig. version 0.1alpha. Use at your own risk.
  11. Converting from sendmail? by marko_ramius · · Score: 3, Interesting

    > There's never been a better time to migrate
    > from Sendmail (just _had_ to get that in
    > there ;).

    So is there any documentation describing a good way to convert from sendmail? Like, how the directives in sendmail map to directives in postfix?

    mr

    1. Re:Converting from sendmail? by bearl · · Score: 5, Informative

      In the source directory there's a text file named INSTALL that has detailed instructions for the three installation options, including "Replace sendmail altogether."

      I won't quote them here in case some of the steps have changed, but it's a very nice step by step list of what to do, what to type, and when to type it.

  12. Re:versioning by Anonymous Coward · · Score: 3, Funny

    You're forgetting the parent post authors theory on the world, Linux is the same thing as Unix, and Linux is the world, with out it, the earth would stop spinning and we'd all be thrown off into space.

  13. missing step by SuperBanana · · Score: 4, Insightful
    [long list of software install steps snipped]

    Nowhere did I see:

    "-read the changelog notes to see if any of the numerous changes classified as "incompatible" affected me or my users".

  14. Postfix Heaven by Chromodromic · · Score: 5, Informative
    I just finished installing and configuring Postfix with TLS, Cyrus SASL, Maildir storage (which Postfix simply "does" by appending a "/" at the end of a mailbox path), and virtual users alongside Courier-IMAP, and, man, was it easy. I had the help of O'Reilly's Postfix: The Definitive Guide and between that, the provided documentation and the wealth of resources available on the Web, I was able to get everything up and running in record time.

    I know this sounds like a commercial, but it's hard not to sound that way when everything just kind've worked the first time. I now have authenticated, encrypted SMTP and POP and my users are, literally, thanking me. My experience has been that using Postfix was an easy way for me to look good.

    Here's a Postfix SASL HOWTO which came in handy, but there are a lot of resources on the Web, especially at the Postfix site.

    --
    Chr0m0Dr0m!C
  15. this SMTP server vs Qmail and Sendmail by astellar · · Score: 3, Interesting

    I use QMail and Sendmail on several hosting servers. Which advantages will my customers get with Postfix ?

  16. insight needed by U.I.D+754625 · · Score: 2, Interesting

    Is it worthwhile to migrate to postfix from qmail? Qmail has a weird license scheme preventing binary distribution that sort of urked me, not to mention hit-or-miss setup documentation, but it's been running great for years now. I've wanted to add some virtual domains and spam filtering and it might just be easier to swap the whole MTA.

    --


    //Blessed are they that run around in circles, for they shall be known as wheels.
    1. Re:insight needed by Xenophon+Fenderson, · · Score: 3, Informative

      I don't see any compelling reasons to migrate if everything is working fine in Qmail.

      If you want a cookbook on how to set up Postfix and SpamAssassin and friends, there are several really good resources: Jeffrey Posluns, Jim Seymour, Meng Wong (old but still useful). Posluns' guide is probably where you should start first.

      --
      I'm proud of my Northern Tibetian Heritage
    2. Re:insight needed by ahodgson · · Score: 2, Informative

      Postfix + Amavis is a wicked combo for content filtering. For virtual domain admin, check out Jamm. If you want great POP/IMAP mailbox support for your virtual domains, add Courier IMAP to your setup.

      Some of the features you might like in Postfix over Qmail include SMTP AUTH, TLS/SSL support, nice content-filtering support, great spam blocking features (HELO checking, RHSbl support, DNSbl support, sender address checking, many others), and extensive database and LDAP support. The virtual domain support is full-featured, although very different to Qmail's in terms of implementation, and with something like Jamm your users can have full control of their domains and/or mailboxes via a web interface.

      And yes, I know there are patches for Qmail to do most or all of the above. It's just easier to do with Postfix IMO.

  17. SASL, spam, viruses by gtoomey · · Score: 2, Insightful
    SASL authentication was a shocker to get working with Postfix. Some people had not problems, but Murphy'y Law meant I never got it working properly. Lets hope its fixed.

    And it looks like content filtering (spam & virus filters) has been improved with version 2.1

  18. Developers?? by shift · · Score: 3, Insightful

    Why is this in the developers section? Wouldn't it be more appropriately placed in a topic for system administrators?

  19. Real-time filtering by DustMagnet · · Score: 5, Informative
    Cool, what's that about? I found this written by Wietse Venema the author/maintianer for postfix:
    When used with a real-time SPAM filter, this approach allows Postfix to reject mail before the SMTP mail transfer completes, so that Postfix does not have to return rejected mail to the sender. Mail that is not accepted remains the responsibility of the client.

    In all other respects this content filtering approach is inferior to the existing content filter (see FILTER_README) which processes mail AFTER it is queued.

    The problem with real-time content filtering is that the remote SMTP client expects an SMTP reply within a deadline. As the system load increases, fewer and fewer CPU cycles remain available to answer within the deadline, and eventually you either have to stop accepting mail or you have to accept unfiltered mail.

    Too bad it doesn't have a counter attack mode, yet.
    --
    'SBEMAIL!' is better than a goat!!
  20. Sendmail upgrade? by Anonymous Coward · · Score: 5, Informative
    There's never been a better time to migrate from Sendmail
    It seems Exim 4 was released Feb 2002. It includes IPV6, TLS, and SMTPAUTH via PAM, LDAP, MYSQL, PostgreSQL and more.. There is also client rate limiting, and realtime spam/virus filtering no need to accept and bounce junk.
    If you're using Postfix and have been waiting for any of these "new features", go ahead and try Exim.
    Exim home page
    1. Re:Sendmail upgrade? by Zapman · · Score: 3, Informative

      Every single one of these has been in postfix for at least 2-3 years. They have been UPDATED in postfix 2.1, not new features.

      --
      Zapman
    2. Re:Sendmail upgrade? by Anthony+Boyd · · Score: 2, Insightful
      It seems Exim 4 was released Feb 2002. It includes IPV6, TLS, and SMTPAUTH via PAM, LDAP, MYSQL, PostgreSQL and more.

      I wrote a Perl-based whitelist program. My biggest problem in the Exim vs. Postfix wars is that Exim (at the time I wrote the whitelist app) doesn't offer all the status codes that Postfix does. So my ability to bounce email with informative messages is limited in Exim. Postfix, no problem. But since you seem to know all about Exim's features, what can you tell me about the last 18 months of development? Do it offer more in the way of response codes?

  21. SMTP time scanning, finally. by stevenbdjr · · Score: 5, Informative
    real-time content filtering _before_ mail is accepted

    About time. I've been doing this with Exim and Exiscan for almost 2 years now. It's nice to see other MTA's begin to incorporate this functionality. Now, if everyone upgrades and takes advantage of this wonderful feature, maybe the number of false NDR's I receive due to forged senders will start to go down...

  22. Re:versioning by hmallett · · Score: 2, Funny

    Gimp hackers...
    Don't pick on them just because of the version numbers they coose, you insensitive clod...

  23. The Doc by anarcat · · Score: 5, Informative

    Yeah, that's good. I always had trouble finding my way into the postfix documentation, now it's a lot clearer. I especially like the listing of all main.cf settings (now if there would be a manpage for master.cf too...) and the bottleneck analysis tool.

    I do miss however the "big pictures" yellow + blue graphs that seduced me into trying out postfix long time ago. Now we're stuck with pityful text-only rendering

    Still great, after all those years, postfix is my MTA of choice: ease of use, power and security.

    --
    Semantics is the gravity of abstraction
  24. Re:this SMTP server vs Qmail and Sendmail by Just+Some+Guy · · Score: 4, Informative
    It's Free Software (unlike Qmail) without Sendmail's security record (unlike Sendmail).

    Personally, I still use Sendmail everywhere, but Postfix is designed to be a fast, secure, easy-to-configure MTA. It would be my migration path of choice if I were ever having problems in any of those three areas.

    --
    Dewey, what part of this looks like authorities should be involved?
  25. Re:Great software, bad hardware by bigberk · · Score: 2, Informative
    When that old CPU fan craps out, a fast Postfix will do no good.
    You're absolutely right. We're in the process of moving to some proper FreeBSD colocated servers (but then, what will I do with all the spare computing power)?
  26. Re:Linux Kernel by gowen · · Score: 2, Funny

    Its the other way round with /. UIDs. Odd numbers are gurus and geniuses, even numbers are dweebs and wannabes. Its a pretty clever algorithm that gives them out.

    --
    Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
  27. Postfix + TLS/SSL + SMTP-AUTH HOWTO by phoxix · · Score: 4, Informative

    Hi guys,

    Postfix + TLS/SSL + SMTP-AUTH HOWTO

    I wrote this howto a while back ago. It explains what is needed to be done in setting up a secure Postfix SMTP server with TLS/SSL and SMTP-AUTH. It isn't fully done (but the meat is there). I hope someone will find it useful.

    Sunny Dubey

    PS: no I have *not* submitted it to postfix.org, for it is not done, and its doesn't have all that I want in it. (Must add virus/spam scanning to it first)

  28. Grudgingly going back to Sendmail. by IGnatius+T+Foobar · · Score: 4, Interesting

    One of my servers is a big Sparc box (running Linux, not Solaris) that performs backup MX and other relay services for about a hundred domains at a hosting center. It gets constantly pounded on all day long. Originally it ran Sendmail, and it was badly loaded down. Installing Postfix cleared up all the problems. It's just that much better.

    Unfortunately, with all the extra mail traffic now due to MORE spam, MORE viruses, and all the bounces generated by the above, we have to expand again. And we have to go back to Sendmail because of one particular feature: you can have multiple Sendmail instances sharing an NFS-mounted queue. Since the new system is multiple Sparc boxes in a load-balanced cluster, we have to go back to Sendmail because Postfix doesn't support this. :(

    --
    Tired of FB/Google censorship? Visit UNCENSORED!
    1. Re:Grudgingly going back to Sendmail. by DavidTC · · Score: 3, Informative
      Why the hell are you sharing a mail queue? It's not like more than one server can send the message at a time, or receive it. And postfix supports NFS mailboxes just fine.

      And why the hell are you bouncing spam? Delete spam or reject spam, do not bounce spam.

      It sounds like you don't know what you're doing, or have a really stupid setup.

      And, BTW, if you're getting hammered because you're the backup MX, which spammers like to pound, it might make sense to set up a tertiary MX server that doesn't actually exist. Spammers will go after that, instead, and never hit you, as almost all spamming software is written by complete fucking morons. Whereas actual mail that failed to get your primary server will just your backup. (Or, failing to get your backup, they will then fail to get your tertiary and just queue the mail, and start back over when they retry.)

      I, personally, set up a 'backup MX' record to point at one of my IPs that didn't actually run a mail server, and cut my daily spam attempts by 30%.

      --
      If corporations are people, aren't stockholders guilty of slavery?
    2. Re:Grudgingly going back to Sendmail. by gnuman99 · · Score: 3, Insightful

      Uhhhm, why now just use the cluster to filter stuff, and then just map the mail to an internal SMTP server which moves the traffic to user accounts. That way your cluster will not need to use NFS, but just their own disks (which is faster, most of the time), and the internal SMTP server will not get loaded that much since it does nothing that CPU intensive (no filtering).

    3. Re:Grudgingly going back to Sendmail. by Azghoul · · Score: 3, Insightful

      Way to help the guy actually learn something. Real friendly there, buddy.

      Too bad the rest of us aren't experienced mail administrators like you are.

    4. Re:Grudgingly going back to Sendmail. by Just+Some+Guy · · Score: 2, Informative
      Some brain-dead spam broadcasters pick MXes at random to deliver to, and some deliberately target lower-priority exchanges (the idea being that a mailserver may be less picky about mail it receives from one of its backup MXes than other hosts). If a low-priority MX is listed but doesn't really exist, the spammer may attempt to deliver mail to that MX, and then give up when it fails.

      It's kludgey, broken, and something I wish I'd thought of earlier.

      --
      Dewey, what part of this looks like authorities should be involved?
    5. Re:Grudgingly going back to Sendmail. by IGnatius+T+Foobar · · Score: 2, Informative

      So much flamebait, so little time...

      Why the hell are you sharing a mail queue? It's not like more than one server can send the message at a time, or receive it. And postfix supports NFS mailboxes just fine.

      One server, one message? We're talking hundreds of thousands of messages per day spread out over dozens of individual mail systems. There are no local mailboxes -- this is strictly a relaying system.

      I, personally, set up a 'backup MX' record to point at one of my IPs that didn't actually run a mail server, and cut my daily spam attempts by 30%.

      And you probably dropped the reachability of legitimate mail too. I'm sure that works well in your little playground, but this is a real environment and we have SLA's to honor.

      --
      Tired of FB/Google censorship? Visit UNCENSORED!
    6. Re:Grudgingly going back to Sendmail. by DavidTC · · Score: 2, Insightful
      And I suppose you have some explanation of how having an unreachable backup MX lowers your chances of getting email to your primary MX?

      ...

      I thought not. SMTP doesn't work that way. A mail server tries all possible MX servers, in order.

      If my primary is, for god know what reason, unreachable, then it wastes a single second of the mail sender's time to check the backup before queueing the mail. That's the entire net effect. You'll get your delayed mail a second later, in theory, which doesn't actually happen because no one runs around setting retry timers that trigger the exact second anyway.

      As for relay servers...you need hundreds of those why, exactly? You're operating one of those crazy-ass overloaded networks, apparently, where mail bounces through two or even three SMTP servers both going in and out.

      Those networks are brokenly designed. Sorry, but it's true. I understand why you can't fix them at this point, but it doesn't mean they were designed correctly.

      There's absolutely no reason not to have a single incoming point (Or even sets of points, via NFS directories.) for each account, where a message comes in and is stored 'locally', and absolutely no reason not to have one outgoing server for each outgoing message, when then sends the message directly to the recepient. (Those can be the same system, or not.) And maybe backup MXs for collecting mail when the system is down. No one has ever explained to me why a mail system needs to be more complicated than that. Anything more complicated than that is probably just historical nonsense laying around.

      --
      If corporations are people, aren't stockholders guilty of slavery?
    7. Re:Grudgingly going back to Sendmail. by DavidTC · · Score: 2, Informative
      Because someone's a loon who's made an amazingly complicated mail system, that's why.

      He's not only building relay servers that transfer mail between themselves, which there is absolutely no reason to do, (They should accept mail from X and forward to Y, not play hot potato with it. Having more than one server is fine, but they don't have anything to say to each other.) he's making them transfer mail between themselves using the mail queue instead of SMTP.

      Which is rather akin to setting up a shuttle bus system between the airport and a hotel, realizing you need more than one bus to handle the load, and coming up with the 'solution' of running each bus halfway and transferring all the passengers at the midway point. Each bus driver only needs to be able to handle half the route, think of all the time and training he'll save!

      With postfix, of course, he'd have to build a delivery station to offload the passengers to, but with sendmail, he apparently can transfer passengers directly from bus to bus! (Which, despite sendmail's shortcomings, I doubt was intentional.)

      --
      If corporations are people, aren't stockholders guilty of slavery?
    8. Re:Grudgingly going back to Sendmail. by DavidTC · · Score: 2, Informative
      That's exactly what I said. You've built a system where one system will accept a message, and then one system will attempt to deliver it, which provides no benefit at all over having one system deliver it from start to finish, except you've added race conditions and file sharing and waste all around.

      As for talking about deleting things out of the queue, that's just crazy. There are commands to do that, and they run just fine remotely. (Not that running around deleting mail from a delivery queue is a normal action in the first place, and I suspect you came up with that because you know what you're talking about is silly.)

      --
      If corporations are people, aren't stockholders guilty of slavery?
    9. Re:Grudgingly going back to Sendmail. by DavidTC · · Score: 2, Insightful
      That's what I'm saying.

      If you're having an excessively large volume of mail, and want to add more relay servers, the solution is to add more identical servers with round-robin DNS, and possibly a larger pipe.

      Having them pass mail among themselves via a shared NFS server isn't going to help anything at all. The ideal solution would be to have most mail in and out in ten seconds.

      And, if large amounts of undeliverable mail are piling up, a shared queue just hurts things, not helps them. That just means every server will check every message to see if it's time to deliver it, repeatedly. Over the network.

      Now, if he wants to do something sort of like this that actually help, a solution would be what postfix calls a 'fallback relay'...a server where mail that can't get delivered in X time goes. Where you can have some extra sanity checking that will quickly delete mail that can't ever be delivered, but you don't want to run on every message.

      --
      If corporations are people, aren't stockholders guilty of slavery?
  29. Re:this SMTP server vs Qmail and Sendmail by DavidTC · · Score: 5, Informative
    qmail isn't free software because it's non-forkable.

    You can freely redistribute the source and binaries compiled from clean source. And you can distribute patches to it.

    However, the point is, the qmail maintainer is the only person who can release new versions of qmail. And hence it's not free software.

    There are two very large dangers with qmail...that it will go off in a random direction no one agrees with, and you'll either have to follow along or go that way, and that the qmail maintainer will just stop releasing new versions. With free software, if enough people use it, they will simply make a fork...but they can't do that with qmail. Technically they could grab a random version and keep building patches off that, but that becomes unmaintainable real fast.

    In other words, qmail is basically 'freeware', not 'free software', although it does come in source form, and you have been granted the ability to modify it and even share the modifications. But not the end result.

    --
    If corporations are people, aren't stockholders guilty of slavery?
  30. Re:Great software, bad hardware by wagemonkey · · Score: 2, Interesting

    I'm sure someone can come up with a joke about beowulf clusters....
    Shift some services to it, network monitoring, security scans. Stuff you can easily run somewhere else if it dies but it's handy not to. Or donate it to a charity that wants it. MP3 server, CD jukebox server. Write something spiffy to act as a voicemail system...

  31. Re:this SMTP server vs Qmail and Sendmail by rsidd · · Score: 4, Insightful
    Just like KDE is not Free Software because it is based on Qt, which has a comercial license?

    I wonder when people will stop repeating this rubbish. Qt has been GPL'd for years. It is also available under a commercial licence, but that has nothing to do with KDE, it's in case you want to develop a closed-source application with Qt. (And it seems to be an excellent business model.)

    As for qmail, you're not allowed to distribute modified versions, and the rules on distributing binaries are rather stringent and almost impossible for distributors to follow. That makes it not quite "free software" (by FSF's definition) or "open source". (However, you're allowed to distribute patches, and even bundle patches with unmodified source in a tarball; you can download one such tarball, called netqmail, from http://www.qmail.org).

  32. Postfix's new policy server API by RonBurk · · Score: 5, Interesting
    One of the geek-cool things about this release of Postfix is that it finally provides a way to add your own code to the SMTP conversation without having to understand or patch Postfix at all.

    The new policy server interface is a simple sockets-based API for getting a chance to participate in the SMTP conversation as it is happening. The basic idea is:

    • tell your Postfix config file (main.cf) that you've written a "policy server" that listens on a particular Unix socket or TCP address/port. You can have the policy server get "called" at any of the points in the SMTP conversation where Postfix may make a decision about how to dispose of the message (HELO, RCPT, etc.).
    • write your policy server. It listens for connections, and each connection sends you one or more requests. Each request contains a small set of information about the mail message being transmitted (client name/address, HELO text, etc.) Your server responds with one of a broad set of actions that Postfix supports (reject, accept, defer, perform other custom checks, etc.).
    • The protocol for talking to your server is a simple text-based protocol with newlines, much like the form of HTTP. I coded an initial policy server in good ol' C in about an hour.
    In particular, this new API is a great place to implement greylisting. Your server can maintain its database of whitelisted and greylisted from/to/IP triplets all on its own and just respond to Postfix requests. And, once you've coded up your policy server, you don't have to revise it with every Postfix patch that comes down the pike. As long as the API remains backwardly compatible, your policy server code should survive any Postfix upgrades.

    Kudos to the new policy server API!

  33. Re:this SMTP server vs Qmail and Sendmail by stilwebm · · Score: 3, Informative

    It is also important to note that Postfix provides Maildir support for local delivery. This means you can have nested folders (containing both messages and more folders) on your IMAP server, where as with Sendmail's mbox format you can only have folders containing messages, and those folders are actually just long text files. Qmail provides the maildir format natively, but Postfix makes it free.

  34. When next you announce.. by Anonymous Coward · · Score: 5, Informative

    The latest version of an application... how about including a link to the release notes / changelog. No point in upgrading if you don't know the changes - RELEASE_NOTES

  35. Re:Great software, bad hardware by wagemonkey · · Score: 2, Interesting

    Did 200MHz Pentiums have CPU fans, or just heatsinks?

  36. Re:this SMTP server vs Qmail and Sendmail by kweber666 · · Score: 5, Informative

    There are two very large dangers with qmail...that it will go off in a random direction no one agrees with

    There is another theory which states that this has already happened.

    and that the qmail maintainer will just stop releasing new versions

    To quote the qmail web site: The latest published qmail package is qmail-1.03.tar.gz, which was released in June 1998. So again, this may have happened already.

  37. Like sendmail's milter? by dmeranda · · Score: 3, Interesting

    It's great to see this feature added! I've been using sendmail's milter feature (a very similar sockets-based "policy" API) for many years. And I can't live without it now, and there was no way I would even consider looking at any other MTA that didn't have a similar feature. I program my milter's in Python, a bit easier than C. But you should have your choice.

    Of course I'm one of those very happy sendmail administrators (we do exist), and I have a relatively complex setup handling hundreds of thousands of messages per day, with very complex routing, etc. But perhaps Postfix is finally serious about providing an alternative (of course I also need TLS and IPv6 built-in like sendmail's had forever).

  38. Where's ZMailer? by Anonymous Coward · · Score: 2, Interesting

    What's happened to ZMailer? This thread has lots of mentions of postfix, exim, sendmail, and qmail, but I thought zmailer was supposed to be a big deal in mail server land... Has it been surpassed and forgotten now?

  39. Nice that MacOS X now uses Postfix by wfolta · · Score: 4, Interesting

    A pleasant surprise in the 10.3 was the adoption of Postfix. It's good to see that they apparently made a good choice and good things are happening on the Postfix front.

    (I had been rooting for exim, which is also a great package, but Postfix seems to be a good alternative. Maybe they should also include exim on XServe's?)

  40. Why all the MTA anti-sendmail holy wars? by dmeranda · · Score: 4, Insightful

    I've been using sendmail for nearly 15 years in some pretty complex environments, and am pretty happy with it. But I have nothing against Postfix either (except it has been lacking features, for me, and sendmail works just grand).

    I can't quite understand the religous flame wars over MTA choice either. I mean, I can kind of understand the whole emacs vs. vi or gnome vs. KDE. But why fight over MTA's? It seems there is an awful lot of hatred for sendmail, and for no good reason whatsoever. It's just stupid.

    I think a lot of it has to do with sendmail having such a long and rich history; anything which has existed for over a decade tends to get a lot of newbie disapproval. Also the configuration can be rather complex, and I think most people who flame about sendmail just don't want to 'fess up to being too dumb to understand it (with my asbestos suit on), and so resort to juvinile name calling.

    Also you have to remember that probably 95% or more of the /. readers never use an MTA in anything but the simplest of configurations. Most likely a home computer or a small LAN. Those who have to manage email for large corporations in very complex networks, etc., can appreciate all that raw power and flexibility of sendmail much more. But to most, it seems like an overly complex mess.

    And about the security-flaw reasoning. That's just an easy way for flammers to badmouth sendmail without really giving true reasons. Any software which has had such a long history and unbiquitous use as sendmail has a history of security flaws. For that matter Unix itself has had an absolutely abismal security record. And yes, someday Postfix will have it's own history to brag about too. But in all cases the flaws were quickly fixed, and the vast majority of flaws required a very specific configuration to even be a problem. Also many security problems result from improper installation; you can run sendmail in a very security setup if you want (just avoid all the FUD about sendmail). You can't compare Postfix and sendmail based solely upon their history of security, because sendmail's history is decades longer than Postfix's. And sendmail has processed perhaps a million trillion times as many email messages as has Postfix over it's lifetime.

    1. Re:Why all the MTA anti-sendmail holy wars? by johnnyb · · Score: 4, Insightful

      It's not the flaws, it's the architecture and development methodology, although I've heard both have been revamped in 9, I haven't checked myself.

      Postfix has several security policies:

      1) no process will ever _touch_ user data as root
      2) all data is converted into fixed-length records for internal use
      3) each program is small and does one task using the least privilege concept

      There are others, but I can't think of them right now. Up until V8, sendmail had the monolithic, let's-run-everything-as-root concept. It's not that sendmail has flaws, it's that sendmail is so susceptible to flaws just by its design.

      Again, I'm not aware of the improvements done in V9, as I had already switched to Postfix.

    2. Re:Why all the MTA anti-sendmail holy wars? by dmeranda · · Score: 2, Interesting

      Then you really need to check out the latest sendmail. It is WAY better than older releases. I think most of the FUD against sendmail is because nobody is looking at it's current features or design, only what it *was* say 5 or more years ago. Sendmail has not stood still.

      It uses capabilities, chroot jails, etc. It is nowdays very good about running with least priviledge, and only a very small kernel of code ever runs with root priviledge in a proper setup anyway. (or if at all if you OS supports capabilities).

      The one potentially bad thing about your mention of Postfix using fixed-length records, is that is usually the root cause for buffer overflows. I'm not saying that Postfix is suseptible or not, but actually fixed-length records is not necessarily a universally good security policy. But at least Postfix has some policies, so I have nothing against it. I just can't stand sendmail bashing without the facts.

    3. Re:Why all the MTA anti-sendmail holy wars? by johnnyb · · Score: 4, Insightful

      "The one potentially bad thing about your mention of Postfix using fixed-length records, is that is usually the root cause for buffer overflows."

      Incorrect. What Postfix does is BREAK UP a message into fixed-length pieces so that a buffer overflow CANNOT occur.

      Buffer overflows are a problem when you ASSUME that a field is of X length but it's actually Y. Since Postfix breaks up lines into fixed-length quantities, it prevents lots of potential problems because there is no way that a line could overflow.

  41. OTOH.. by slittle · · Score: 2, Informative
    The latest published qmail package is qmail-1.03.tar.gz, which was released in June 1998. So again, this may have happened already.
    May also be read as: no known exploits for >= 5 years.
    --
    Opportunity knocks. Karma hunts you down.
    1. Re:OTOH.. by ahodgson · · Score: 4, Interesting

      Unfortunately, it has also meant no new functionality for >= 5 years, unless you want to maintain your own source tree with dozens of patches.

      I loved qmail, but all my systems run Postfix nowadays. SSL, SMTP AUTH, content filtering, too many features I needed and qmail doesn't have.

      I just hope djbdns doesn't go the same way, cause I REALLY hate BIND.

  42. Re:this SMTP server vs Qmail and Sendmail by dasunt · · Score: 3, Informative

    It is also important to note that Postfix provides Maildir support for local delivery. This means you can have nested folders (containing both messages and more folders) on your IMAP server, where as with Sendmail's mbox format you can only have folders containing messages, and those folders are actually just long text files. Qmail provides the maildir format natively, but Postfix makes it free.

    Or you can use Sendmail + Procmail for Maildir-style storage.

  43. Not a compelling reason to switch. by lorcha · · Score: 2, Informative
    You can easily do virtual domains and spam filtering in qmail. Virtual domains you can read about in "Life With Qmail". For spam filtering and virus checking,

    apt-get qmail-qfilter clamav spamassassin

    and you're there. On the other hand, you may have other reasons to change MTAs. I'm actually thinking of switching from qmail to courier since I already use courier for IMAP, so it just makes sense to use the courier MTA, too. Also, like you, I hate the oddball qmail license. I also hate the way qmail installs weird shit all over my system. Come to think of it, I don't even remember why I chose qmail other than the hate of sendmail.

    Blah.

    --
    "Avoid employing unlucky people - throw half of the pile of CVs in the bin without reading them." -- David Brent
  44. Re:this SMTP server vs Qmail and Sendmail by Kent+Recal · · Score: 2, Interesting

    Well, having a stable target for patches and extensions can be a nice thing, too.
    And if you're dealing with mailing lists (from the admin side) you definately wanna take a look at ezmlm.

    I haven't tried postfix in a while but I guess the old rule of thumb (for small sites use whatever, if you need it big stick with qmail) still applies?

  45. Re:this SMTP server vs Qmail and Sendmail by Rabbitt · · Score: 4, Insightful

    Postfix is -not- written in perl. Postfix is written in C. Please, in the future, at least -know- what you are talking about before posting.

    --
    Carl P. Corliss
  46. Re:this SMTP server vs Qmail and Sendmail by Anonymous Coward · · Score: 4, Informative

    Becuase so many other posts aren't stating this I'll try to explain some of the offerings:

    Postfix is easy to configure. One of it's biggest advantages is that it uses many different type of maps for various purposes. Say I want to tell postfix what domains to relay mail for. I can have it lookup the domains in a traditional dbm/hash file or I can even specify an LDAP server to hit. In addition I can have it do the lookups in any order, dmn static entries first, then hit an old sendmail hash, then finally hit LDAP for my new point and click allocation system. This same mapping system is identical for almost all configuration parameters, aliases, virtual domains, virtual alias, maildir/mbox locations, valid recipients, valid senders, SMTP Auth users, etc., etc.

    In addition I like postfix's rate control system. Postfix will notice when a foriegn mail system is under load (judged by its response times) and throttle back the rate and number of connections to it. This means that there is less of a chance that mail will be rejected with a temporary failure by the foreign server because it's too busy. It avoids the mail being moved from the active queue to the deferred queue imposing an hour or so delay until the next delivery attempt.

    This also works for inbound mail. I can set rate limits so that if a foreign mail server tries to bomb me, postfix will notice this and throttle the connections. It does this by imposing mandatory delays in confirming the delivery to the foreign server. Again, the rates and thresholds are all configurable.

    Postfix has some nice security features. For instance one feature is From: validation. All my users must log into postfix using SMTP Auth before sending mail. I have an LDAP map that specifies the allowable From: addresses the users are allowed to use. If the From: address doesn't match what's configured for the SMTP Auth user, the message is rejected. This keep users from spoofing other user's addresses in the From: header. In addition to validating the recipient domain, postfix can validate the recipient address before the message is accepted. Again, from any map type, including LDAP.

    Postfix also has a sendmail compatibility layer. Meaning sendmail commands like 'sendmail' and 'mailq' typically work exactly like their sendmail counterparts.

    As for performance and scalability, it's right up there with Qmail and sendmail. Performance on my particular servers will be less than on a plain Qmail or sendmail setup, but I also perform tons and tons more checks and validations on each message. Each message results in about 4 LDAP lookups and also gets piped through Amavis-new, Spamassassin, and ClamAV. The idea that postfix is for small to medium sized servers is a wash. It has a feature set that is above and beyond the rest and I'm quite impressed with it.

    I used to be a die hard sendmail guy. But after going to postfix, I'll never go back.

    My $.02 anyhow....

  47. netqmail-1.05.tar.gz by Russ+Nelson · · Score: 2, Informative

    http://qmail.org/netqmail/

    'nuff said. Trolls, heh, ya gotta love 'em.
    -russ

    --
    Don't piss off The Angry Economist
  48. Re:Great software, bad hardware by Ctrl-Z · · Score: 2, Interesting

    My 486 had a CPU fan. Then again, it didn't really need it since it ran for about 3 years after the fan died on it. On the other hand, the power supply only ran without a fan for about 6 months before it died. Ah, the glory days of computing.

    --
    www.timcoleman.com is a total waste of your time. Never go there.
  49. Re:this SMTP server vs Qmail and Sendmail by zulux · · Score: 3, Interesting



    To be fair..

    Qmail is *very* well deigned and programmed. There's hasen't been a real need to issue a new package for a long time.

    I still don't like the license - but it is damn fine software.

    --

    Moneyed corporations, non-working 'poor' and criminal prisoners are turning productive citizens into tax-slaves.

  50. parent is so wrong, it's not even funny by Kunta+Kinte · · Score: 4, Insightful
    I was going to mod you down, but I figured I corrected you instead.

    It is not the MTA's (Mail Transfer Agent) job to put the mail on the filesystem, that's the MDA's (Mail Delivery Agent) job. Sendmail is a Mail Transfer Agent. Sendmail, for as long as I've known, as a pluggable MDA format, where you can put in any MDA you choose. You can easily build your own MDA for Sendmail. Not to mention if you use Milter.

    This is rudimentary internet mail handling.

    For example, I use Cyrus IMAP's MDA with sendmail; and thus sendmail simply hands the Cyrus MDA my mail once sendmail has figured the mail belongs on this server.

    Thus in a way, Sendmail, Postix, and all other MTA are essentially routers.

    --
    Based on upvotes, Ageism is the only "-ism" Slashdotters care about and think isn't SJW
  51. Excellent Postfix Setup Guide by jwbrown77 · · Score: 2, Informative

    Here.

    The HOWTO is based on Gentoo, but the configuration principles can obviously be used on any machine.

    --

    -----
    How can you have any pudding if you don't eat your meat?
  52. Re:this SMTP server vs Qmail and Sendmail by ePhil_One · · Score: 3, Interesting
    I still don't like the license - but it is damn fine software.

    It may be damn fine software, but its creator has decided that he doesn't like the existing init systems on linux/BSD and so has written his own. That right there took qmail out of consideration. I don't care if he is right or wrong, I have no intention of installing a second init system just so I can run his software. The creators of Postfix integrate beautifully with linux standards, Redhat even provides a well integrated postfix package (install the rpm's then run 'redhat-switch-mail'). Not to mention the awesome 'mailgraph' utility - http://people.ee.ethz.ch/~dws/software/mailgraph/ for charting stats!

    And best of all, its wicked fast. I can handle 100's of msg per minute on a 500Mhz box, which I learned the hard way that sendmail can't.

    --
    You are in a maze of twisted little posts, all alike.
  53. Re:this SMTP server vs Qmail and Sendmail by sumbry · · Score: 4, Interesting

    Having worked at a hosting company for years, we actually migrated to Postfix (from Sendmail) way back in the day, when Postfix was still called VMailer (actually joined the beta before it even had a name).

    Simply put, Postfix is designed from the ground up with security in mind as well as the KISS philosophy of software design. Postfix has a bunch of little programs that all do one thing and do it very well, is realitively easy to chroot and even if you opt to not do that is still much more secure than Sendmail (esp its out of the box config). It's author Wietse Venema (sp?) was the same guy that wrote TCP Wrappers which is a stock part of almost every BSD/Linux distro today.

    Postfix was engineered from the groupd up to be a Secure MTA and was able to take immediate advantage of all the lessons that had been learned by Sendmail w/o having to hang on to a legacy codebase.

    Postfix is also extremely easy to configure, using straight non-cryptic ini style conf files and doesn't require a 1300 page manual to get the best out of it. Couple this with the fact that connecting it to a MySQL/Postgres/Oracle database for map lookups (forwarding, alias, transport, etc) and you've got this beast that scales very well for hosting environments (you can also used virtual passwd databases enabling you to create mailbox accounts that do not actually exist in the systems passwd db). When we deployed it at said hosting company, we were delivering close to a million messages a day and saw lookup times, delivery times, queue times, pretty much everything drop to about 1/4 of their levels w/Sendmail. Postfix is blazingly fast.

    Postfix isn't for everyone tho. If you're only running a few domains and/or Sendmail came preconfigured on the box you're running it on then you're probably fine sticking w/Sendmail. We actually only used Postfix as a hub and used Sendmail on all our severs in a relay only mode. If you know Sendmail back and forth and can make it jump through flaming hoops I wouldn't necessarily advise switching to Postfix unless you're looking to wring more out of your MTA and want to do it relatively easily and securely.

    Someone correct me if I'm wrong, but I don't think Postfix has even had any remote exploits (it doesn't run as root out of the box)?

  54. Re:this SMTP server vs Qmail and Sendmail by sumbry · · Score: 2, Informative

    To add to this, Postix is not just for small to medium sized servers. It actually scales extremely well because of it's design philosophy (bunch of small programs that each do one thing and do it well communicating w/each other).

    I would actually argue the opposite of parent - use Sendmail if it came preconfigured on your box, but otherwise if you're running a large server or hub, migrate over to Postfix if you want to wring every ounce possible outta your mailserver.

  55. Bogus backup MX servers by mattrope · · Score: 4, Interesting
    I, personally, set up a 'backup MX' record to point at one of my IPs that didn't actually run a mail server, and cut my daily spam attempts by 30%.

    And you probably dropped the reachability of legitimate mail too. I'm sure that works well in your little playground, but this is a real environment and we have SLA's to honor.

    Actually, using an unreachable backup MX is an excellent idea and shouldn't affect legitimate email at all. Real mail servers (i.e., servers running software like sendmail, postfix, exim, etc.) will try to deliver a message to each MX server, from high priority to low priority, until they find one that is accessible. So if he sets up a bogus MX server at the lowest priority, all of his other MX servers will still be attempted (and if they're all down for some reason, he's screwed anyway). However, spammers often use custom mass-mailing software that isn't smart enough to try all MX servers. In fact, their software seems to specifically target the lowest priority MX servers, probably because they think these servers will be less likely to inspect and reject the message at SMTP time. So if your lowest priority MX server is bogus and doesn't really exist, spammer software might not be smart enough to actually try the other MX servers; it will give up and move on to the next victim.

    So using this technique shouldn't affect legitimate email, but it stands a good chance of cutting down on some spam. I'm glad he posted it.
  56. Obligatory beowulf joke by aulendil · · Score: 3, Funny

    First, a morpheme attached to the end of a word isn't unbound, it is bound. Second, what you seem to mean by postfix is usually called a postposition (contra preposition), as in ... drum roll ... Beowulf:

    Scedelandum in , in scandinavia.

  57. Re:this SMTP server vs Qmail and Sendmail by zulux · · Score: 3, Insightful



    I agree myself too. I *like* Qmail better than Postfix... but I realise that Postfix has a gurenteed future so that's what I run.

    --

    Moneyed corporations, non-working 'poor' and criminal prisoners are turning productive citizens into tax-slaves.