When it comes to IMAP servers, there is a near inverse relationship between setup simplicity vs. the ability to handle large amounts of users and mails.
I appreciate you mentioning that. It's such common sense, but it never occurred to me.
The problem is that storing all your mail in a single file is not very scalable. Once you have about 1000 messages in a mailbox, that mailbox becomes painfully slow to open. It is also a bit kludgy - basically, if a line in a mail message starts with the word "From ", then that line has to be altered (to e.g. ">From ") so as not to represent a new message.
Now, this is something that confused me when I 1st saw it. It definitely didn't look like a bad quoting problem. Thanks!
I would like to confirm that I understand what you are saying in the remainder of your comment. Are you saying the following?
Cyrus doesn't provide an option to make use of the maildir format even if we wanted it to do so
we should try to make use of the Cyrus format, no matter what
Exim & Postfix don't deal with the Cyrus format, nativelyCorrect?
Also, are you saying that mutt can actually create a psuedo-IMAP feel when dealing with POP3?
I work for a major university with seven campuses and email supported centrally.
We currently support 180,000 users across 6 four way sparcs. We are somewhere close to 2 TB of mail data. We've been running with an average of 1 unscheduled downtime per year over the past five years.
Wow. Thanks for the info. I think that it helps me to know what you are up against when giving out email advice.
It turns out that we aren't just dealing with our own email, as I may have said/implied in the/. submission. We might actually provide these services to our customers. I guess this brings up a new question. Is it better to have all our customer's email dealt with on our own servers, or should we set up 1 server per customer on each site?
We use sendmail + cyrus, with a few minor modications. We have no plans to move away from the cyrus imap server.
I, being a mail server newbie, haven't heard of any real tangible technical benefits of running sendmail. Why did you guys try it? Would you recommend it to anybody?
Courier's maildir implementation also has problems with large mailboxes, as header indexes are generated from the mail data rather than cached, causing all files to be touched.
If we install Courier for small sites, then will there be a noticable performance difference, as opposed to Cyrus for small sites?
If header information is cached on local disk, the store can still be mounted via NFS. It is a good model, but we've found that IO is the bootleg in large email installations. NFS mailstores would give us flexibility with regards to redundant imap protocol servers, but the resource we are most trying to conserve (IO bandwidth) is still bottlenecked (theorectically at a single server IO throughput, realistically at NFS throughput speeds).
Yeah, in general, I don't like sending stuff over the network, because I like to keep it as free of network traffic as possible. If I understand correctly, that isn't exactly what you were talking about, but I think that the principle applies. Correct me if I'm wrong, though.
I think that I might go with Courier for ease of setup, & then start again with Cyrus to get the performance advantage.
It seems that you are very knowledgable & practical. I really appreciate the comparrisons. I expect that this will be a long term project for our company. Even though I don't really agree with it, it keeps me employed. Besides, you can't complain when you're being paid to research without a deadline.:^)
The Morris worm was able to mutate acrost all hardware archs because it uploaded source code and compiled it.
That is unbelievable. You sound very knowledgable. I appreciate your help.
I must ask, though, wouldn't Gentoo be immune from this specific problem, now that they no longer require that you install by compiling? I think that the question has already been answered, but I want to just confirm from you that there isn't another outstanding [correct terminology] issue.
The whole reason that I want to use Gentoo is the ease of install & upgrading. I had a few bad problems with RH.
how many users will you be supporting
expected traffic volume What are you using for smtp? sendmail/qmail/whatever Which web client are you using?
There are 5-10 in our office, plus admin, postmaster, webmaster, abuse, etc. I can think of 5 right now, but I'm sure that there'll always be more that I didn't think of.
I don't know what kind of volume it consists of, though. It should be around 10 business emails per day per user, plus 100 spams per day per user, plus 100 misc. in total. So, maybe a grand total of 650 emails per day?
Our present SMTP server is being handled by someone else, so I don't know just yet what we have. I have courier installed on a test server.
We don't have a web client set up. I just use Yahoo! to read email, if I need to use the web interface.
I hired a consultant earlier this year to move our 1,000 user Red Hat based email system from sendmail to qmail, install Courier imap, and horde/imp for web access. He charged about $3k.
Or, why do you have to go with IMAP? What about POP3? James (http://james.apache.org) is a nice mail server, easily customizable too if you know Java.
Because the boss & others use more than 1 computer in different buildings, plus he wants to administer the business when he travels across the continent. From my readings, it just seems to be much more advanced, useful & intuitive to the user.
Also, we don't know Java. I don't want to learn Java just to customize POP3. I'd rather just get a regular POP3 server installed.
No, I haven't, but I have bookmarked the web site, for later. Thanks for your help. I should point out, though, that I don't know anything regarding exchange, but if it is better in a useful way, then I'd gladly consider it.
(I don't work for Suse)
Even if you did, it won't matter, because I just want to have options. So, if you have services that you want to offer, then go ahead & let me know.
I found myself in a similar situation to yours a few weeks back - no real interest/expertise with email, but I had to get an IMAP email server working fast.
Thanks for that comment. It's really something that I needed to hear.
Would you consider yourself an LDAP expert? If so, how hard/easy is it to become 1? If I recall correctly, a guy spoke @ a LUG meeting about LDAP. The overall basic concepts made sense, but most/all details just went over my head.
I don't understand how you & your friend managed to drop costs by so much just by outsourcing. Was it techsupport related, admin costs, & bandwith? Something else? We only have about 5-10 users. Have your savings got anything to do with the number of users?
From a user's perspective both pop and imap should behave the exact(*) same way as long as they're accessing their email from one computer.
Yeah, I understand that. I am using POP3 right now, actually. For my needs, it works really well. In fact, if nobody told us about IMAP, we wouldn't have anything to complain about. However, the boss uses 2 computers, in different buildings, & would like to have access to it from another part of the country [Ontario, as opposed to British Columbia].
Since we wanted to try to handle the email ourselves, it seemed like such a logical choice to just implement IMAP, anyways. After all, we are already making a change, so 1 extra change wouldn't be too much.
OpenBSD, hardened Sendmail from the default install
Like I said, I'm not an expert, but I'm very surprised that they chose sendmail for the default. Why did they do that? Or do you mean sendmail in a figurative way?
And, yeah, I do consulting too. Send me an email if you're interested and we can talk.
Thanks for the offer. I'll keep you & the other fellow in mind, & I'll contact you both to see what you want to offer; that is, if we decide to go with a consultant, & I hope that we do.
I'll probably be serving about 5-10 users, plus postmaster, abuse, webmaster, etc. I can only count up 5 right now, but there'll always be someone to surprise me.:^) Because of the spam, you could easily multiply the number of users by 100-120.
You could, of course, look around and hire a Linux consultant to set it up for you.
I think that I just might do that. Thanks for the link.
I'm surprised that so few people have offered their services. Maybe I didn't make that clear in the submission.
I'm pretty uncomfortable with continuing with POP3. It seems like the best choice for us is to be able to use IMAP so that the users can travel, & check email. In fact, that was the real selling point for IMAP. @ least 1 of the users uses 2 computers, so it would simplify things a whole lot for him. He would like to travel across the country in November, so it would be pretty important to have access to the mail that is already downloaded.
I think that from the user's point of view, IMAP is much more intuitive.
Nothing is written in stone, though. If you know of any advantages to POP3 & are interested doing some advocacy work for it, then by all means, speak to us!:^)
What other properties are you looking for in your email server?
See, that's the question. I don't know!:^) Based on what you said below, though, I can say that I probably want what you have set up.
For my domains(osdev.org and variants) here's the combination I use:
Courier IMAP - Supports Maildir, works well with most IMAP webmail setups, easy to setup, support Secure IMAP
From what I've read, I definitely want maildirs. It just seems like the proper up-to-date choice. The rest sound good too.
Postfix for SMTP - Can offload mail delivery to another program like Procmail, replaces Sendmail
Procmail for Delivery - The Great thing about IMAP is that you have message folders on the server, procmail will allow you to sort incoming mail as it arrives.
Why do you want to offload mail delivery? Performance? Security? Ease of administration? I ask because I'm under the impression that if 1 program [such as Postfix] can do that, then it would be more efficient over all, or in general to just leave Procmail out of it. Maybe I need to read up on Procmail. Doesn't Postfix or the IMAP server allow you to sort out the mail?
Spamassassin - Integrates with Procmail to sort spam into a folder or/dev/null
SquirrelMail - Seems to be one of the best web based IMAP clients around, done in PHP
Yeah, we definitely want some sort of spam control. That's kind of what got us started on this venture. Web mail isn't necessary, but is a bonus if we could get it.
Myself, I'm partial to Communigate Pro, but even then you need some knowledge (DNS MX records and such).
I feel relatively comfortable with DNS MX records & such. From my readings, I think that I can set up a set of records myself. I still have no real experience. Would this be enough to communicate with Communigate Pro, or should I keep reading? Is layman's English enough to talk about DNS MX records?
# cd/etc/courier-imap// If you want to use the ssl capabilities of courier-imap or pop3,// you'll need to create certs for this purpose.// This step is recommended. If you do not want to use ssl, skip this step. # nano -w pop3d.cnf # nano -w imapd.cnf// Change the C, ST, L, CN, and email parameters to match your server. # mkpop3dcert # mkimapdcert
This is a perfect example of what I'm having difficulties with. I don't understand what to do when he says, "Change the C, ST, L, CN, and email parameters to match your server.". That is why I'm really wondering if I should try to pursue this any longer, or just get a professional from here on. Comments? Suggestions?
I'll go & read the documentation right now, but I have to ask, do you have a computer science degree, or any other expertise that made it easy to read the documentation?
I was planning to use Postfix or Exim. I remember trying to get qmail working, & couldn't do it. That was with a totally different distribution, & that was my fault, but it didn't seem to be worth my time. After all the complaints that I read on the Internet, I decided to forget about qmail.
But first, do you realy want to use gentoo in a production machine? It may be fun to recompile everything, but for a production server, especially with something as important as email, gentoo isnt even a contender.
Well, I'm not exactly longing for Gentoo, but I thought that Gentoo really would provide the best, compared to RH & various precompiled distributions. I thought that it would be more stable if I chose only the stable releases. I wouldn't say that compiling would be fun, though.:^) I'm still relatively new to Linux, compared to many of you. What distibution do you recommend for this, & why is Gentoo not even a contender?
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I would like to confirm that I understand what you are saying in the remainder of your comment. Are you saying the following?
Cyrus doesn't provide an option to make use of the maildir format even if we wanted it to do so
we should try to make use of the Cyrus format, no matter what
Exim & Postfix don't deal with the Cyrus format, nativelyCorrect?
Also, are you saying that mutt can actually create a psuedo-IMAP feel when dealing with POP3?
It turns out that we aren't just dealing with our own email, as I may have said/implied in the
I think that I might go with Courier for ease of setup, & then start again with Cyrus to get the performance advantage.
It seems that you are very knowledgable & practical. I really appreciate the comparrisons. I expect that this will be a long term project for our company. Even though I don't really agree with it, it keeps me employed. Besides, you can't complain when you're being paid to research without a deadline.
I must ask, though, wouldn't Gentoo be immune from this specific problem, now that they no longer require that you install by compiling? I think that the question has already been answered, but I want to just confirm from you that there isn't another outstanding [correct terminology] issue.
The whole reason that I want to use Gentoo is the ease of install & upgrading. I had a few bad problems with RH.
I don't know what kind of volume it consists of, though. It should be around 10 business emails per day per user, plus 100 spams per day per user, plus 100 misc. in total. So, maybe a grand total of 650 emails per day?
Our present SMTP server is being handled by someone else, so I don't know just yet what we have. I have courier installed on a test server.
We don't have a web client set up. I just use Yahoo! to read email, if I need to use the web interface.That's interesting. Why did he choose qmail?
Also, we don't know Java. I don't want to learn Java just to customize POP3. I'd rather just get a regular POP3 server installed.
Maybe I misunderstand you.
Thanks again.
Would you consider yourself an LDAP expert? If so, how hard/easy is it to become 1? If I recall correctly, a guy spoke @ a LUG meeting about LDAP. The overall basic concepts made sense, but most/all details just went over my head.
m
I don't understand how you & your friend managed to drop costs by so much just by outsourcing. Was it techsupport related, admin costs, & bandwith? Something else? We only have about 5-10 users. Have your savings got anything to do with the number of users?
Since we wanted to try to handle the email ourselves, it seemed like such a logical choice to just implement IMAP, anyways. After all, we are already making a change, so 1 extra change wouldn't be too much.
Based on what you have said, & what I have said, do you advise that we contract this out, or try to go for it?
I'm surprised that so few people have offered their services. Maybe I didn't make that clear in the submission.
I'm pretty uncomfortable with continuing with POP3. It seems like the best choice for us is to be able to use IMAP so that the users can travel, & check email. In fact, that was the real selling point for IMAP. @ least 1 of the users uses 2 computers, so it would simplify things a whole lot for him. He would like to travel across the country in November, so it would be pretty important to have access to the mail that is already downloaded.
:^)
I think that from the user's point of view, IMAP is much more intuitive.
Nothing is written in stone, though. If you know of any advantages to POP3 & are interested doing some advocacy work for it, then by all means, speak to us!
You say that it is for your home.
What kinds of security issues did you have to deal with?
What kinds of expertise did you have [computer science degree?]?
How long did it take you?
I'll go & read the documentation right now, but I have to ask, do you have a computer science degree, or any other expertise that made it easy to read the documentation?
I was planning to use Postfix or Exim. I remember trying to get qmail working, & couldn't do it. That was with a totally different distribution, & that was my fault, but it didn't seem to be worth my time. After all the complaints that I read on the Internet, I decided to forget about qmail.
How many users do you serve with qmail?
Based on what you have seen from me, do I have enough to start shopping around, or should I still find stuff to read?
m
Yeah, but what difference does it make? It's still not big enough for some women.