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dhammala asks: "I am responsible for setting up and maintaining a mail server for small web-hosting type business. We currently host about 75 domains, around 100 mailboxes and due to the efforts of our sales team, we are wanting to get ready for some great increases in those numbers. I am worried about my current configuration and ease of administration. More importantly (well, at least to the customers) is email deliverability -- it seems that messages delivered to some big players are being marked as SPAM or disappearing altogether. I am asking the Slashdot community for it's insight and advise on 1) if my current choice of software/configuration is a good match for this situation and 2) if there any additional measures I might take to ensure email deliverability?" "Here is an overview of our current setup:

• We lease servers at ev1servers.net.
• The servers are running RHEL ES3.
• We chose to use Postfix and have it configured to support virtual users and domains mapped in MySQL tables. The reference I used to configure this setup is located here. We initially chose Postfix over qmail because it was open and over sendmail because the config files are actually readable.
• I have added in SQLGrey grey-listing for Postfix to provide a simple level of SPAM detection for our users. We are not wanting to deal with the customer service and higher box loads of mail scanning at this time. We might choose to use a 3rd party vendor to do this as needed.
• Messages are delivered locally via maildrop in maildir format.
• Courier IMAP is running to support both IMAP and POP access to the mailboxes.
• Postfix Admin was setup for easy mailbox administration.

For deliverabilty, I have/am taking the following steps:

• I have verified that our reverse IP records are correct
• I have created SPF records for all of the domains
• I have verified that our server is not listed in any blacklists (great scanner at dnsstuff.com)
• I have started to install DomainKeys for Postfix

In doing all of that, I have found that our IP is listed in the BlarsBL. Do I need to be concerned about this rogue list? The IP was there before I even began to setup the box.

I have not yet been able to get DomainKeys to work with Postfix. It was during my configuration attempts that I started to question this setup and wondered if this was the best setup for our situation.. this inquiry has lead to this posting.

In a perfect world, I would have an email server that:

• is easy to administer,
• supports automated mailbox setup/removal (currently I can just insert rows into my tables and the mailbox setup is done)
• supports current technologies, like grey-listing, DomainKeys, etc
• is secure
• makes the best use of system resources -- I want to get the 'best bang for the buck'

So what do you think? If I stick with this setup will life be grand? I am open to something new AND even taking the time to learn a new setup. If I do need to switch to something different, my only concern would be the ability to migrate existing mailboxes and messages over to the new setup.

Are there any other technologies or configurations that I need to implement to support the best deliverabilty rates?"

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 ;)."

apropos asks: "An interesting question came up recently when discussing (yet again) starting an open-source based consulting company: 'How would you design the ultimate virtual office with open source software?' With things like fax, VoIP, web, email, security and office suites all available as open source products, what kind of useful things could be done? One idea that came to mind was emailing answering machine recordings. What would you put into your ultimate virtual office solution?"

Robby Russell writes "Paper books have a tendency to accumulate dust, take up large amounts of shelf space and be a painful reminder that you need to get rid of stuff when moving time comes and you find yourself packing up the same Pascal book for an eighth time. Granted, the book provides a level of self-accomplishment and it's always great to have your best books out in direct sight of anyone who may come over to your home or office. You know the type; the ones who are observant and notice the books that you want the world to know that you've read, as if you were to say, 'Been there, done that.' You can't tell me that you don't put some of them up intentionally. ;-)" Russell is taken with O'Reilly's floating-rental system called Safari; read on for his review of the system. (various) author (various) pages (various) publisher O'Reilly and other participating publishers rating 9 reviewer Robby Russell ISBN (various) summary Technical book rental is here, and you may find the convenience a compelling enough factor to give up the paper versions of the available titles.

O'Reilly has come up with an interesting solution to your lack of physical shelf space: a virtual bookshelf. Safari Bookshelf is a great resource for all things technical. They recently went over 1,000 titles available online, 24/7. Several publishers have joined forces with O'Reilly to provide so many titles. Que, Alpha, Sams, Microsoft Press (and O'Reilly itself) are a few of the big-name publishers that are part of Safari. Currently, 75% of all O'Reilly books are available through Safari. (With plans for adding 10+ books per month, the selection is growing rapidly, too.)

Safari subscriptions can be had in 10-, 20- or 30-slot varieties, depending on how much you care to read (and spend). Prices end up close to $1.50 per slot each month, with slight discounts if you buy annually rather than by the month. (A $9.99/month 5-slot shelf is available too, if you just want to test the waters.)

Recently, I had the privilege of giving Safari a test-run thanks to the generous offer made to user groups.

The website's navigation was fairly easy to grasp, and I was able to start searching for books as soon as I logged into the system. O'Reilly's made browsing pleasant, by listing the main categories and allowing you to branch down into subcategories to find the book you may or may not be looking for.

I was given a 10-book shelf to start my trial of Safari. This account would typically go at $14.99/month (or $159.99/year). The bookshelf is great. You can add a book to your bookshelf and you keep it there for 30 days, after which you can remove the book and replace it with a different one. So, you can have 10 books in your "shelf" at any given time, and switch no more than 10 books a month under this account level. That is 120 books a year for roughly $1.33/book. That's impressive.

It just so happened that I was currently working on migrating from Sendmail to Postfix recently and wanted to read up more on Postfix to see if there was more I could do to keep my server running happily. I typed in "postfix" in the search, and voila! 109 books were found with that word in the title or description. The search results allowed me to View by Book and/or View by Section (which I found really helpful by showing me a section of the book that contained the word "postfix"). I scanned a few more books in greater depth, looking at the Table of Contents of various books and even looking at the books' chapter previews. A lot of text to look at before I even decide on checking out a book. Being in a bookstore wouldn't have been this good: you can't search through a bookstore for a specific keyword in all texts and get back these kinds of results.

After reviewing a small handful of books, I felt comfortable with my decision and checked out the appropriately-titled book by Sams, "Postfix" by Richard Blum and added it to my bookshelf. The book will be on my bookshelf for the next 30 days. Immediately, I went over to My Bookshelf and found myself looking through the same text you would find in the paper version of this book (but in the font face and size that I set in my browser preferences). It lets me print a page, send the page as an email to someone, etc. I was reading about open relays, and added a bookmark to the page which shows up on the "My Safari" personal page listing all the books I have currently checked out. That page also shows recent searches, newly available books, public notes, etc. With a few clicks, I can go from my computer desktop to page 152 of The Perl Cookbook which is quicker than me looking through my library of paper books and finding my place.

I have since added six more books and visit My Safari page roughly 5+ times throughout my day to read more on various topics. All this content available anytime I need it, and I still have spaces left in my bookshelf. They do offer 5-slot Safari Bookshelf for those who don't need 10 books a month, which is probably where I would fall. The great thing is that this is very affordable. (After calculating the costs of all the books I had bought in the past year, I could have paid for and viewed roughly 232 books plus the 8 technical books I bought last year.)

On the downside, colleagues who come by my home or office won't see my new copy of MySQL Cookbook because it is online rather than on my shelf showing another O'Reilly animal. I might have to print out the covers and tape them to my old school books to deal with that for the time being, but I am sure that Safari Bookshelf is how I plan to spend money on technical documentation from now on.

If it were a Tom Robbins book however, I couldn't see myself sitting in a cozy chair reading it on a laptop; this idea only makes sense to me for technical information because I am sitting at my computer anyways -- and where else would I need technical documentation?

If this idea intrigues you, visit O'Reilly's Safari Bookshelf page. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

Andy Murren contributed this review of Richard Blum's Postfix. Powering mail delivery may not be as sexy as programming in exotic new languages, but it sure is important -- Andy gives you the scoop here on how well Postfix (and Postfix) do at the task.

Postfix author Richard Blun pages 542 publisher Sams rating 8 reviewer Andy Murren ISBN 0-672-32114-9 summary Guide to setting up and running Postfix as your MTA.

Postfix is a complete Mail Transfer Agent (MTA) that is meant to be a replacement for Sendmail. Wietse Venema, who works at the IBM Watson Research Center, wrote the program and released it under the IBM Public License. Richard Blum has targeted this book at Intermediate to Advanced users, but he has enough basic information so that even an MS Exchange administrator with no Unix background can get Postfix running quickly.

The book is broken into three sections:

1. Introduction to E-Mail Services and Postfix
2. Installing and Configuring Postfix
3. Advanced Postfix Server Topics

Part I is a nice overview of email, how to use Postfix, how Postfix works and a comparison of Postfix and Sendmail. In chapter 3 'Server Requirements for Postfix' an overview of Unix and Unix commands are covered along with an introduction to bash, gcc and make to bring the non-Unix user up to speed with the tools that they will need.

The chapter on DNS starts by covering the origins of DNS and the basics of how it works. Blum then gives us an explanation of DNS records and how to set them up, including the all-important MX (Mail Exchanger) record. He then gives a brief discussion on how to set up the resolv.conf, hosts and hosts.conf files. The chapter concludes with a quick look at the host, nslookup and dig programs. This chapter serves as a quick reference on getting DNS up and running on a Unix box.

Part II is a detailed section that is the heart of the book. How to set up Postfix is laid out in detail from how to install (both from an RPM file and from source), to configuring it, to logging and blocking UCE/UBE.

One of the sections of the book I was drawn to was on how to set up Postfix as an internal and external mail server for the Small Office environment. This could be for branch offices of a large company (such as insurance offices) or for a Small Office / Home Office (SOHO) that does not have a full time Internet connection. Blum explains how to set up the server for dial-up to send and retrieve mail, and how to run the mail server on the same box as your firewall.

The chapter 'Migrating from Sendmail to Postfix' is a short step-by-step on how and what to convert from Sendmail to Postfix. Since Postfix was designed to do this easily the chapter is shorter than might be expected (only 20 pages).

Rounding out Part II is a chapter on the Maildir mailbox format and a chapter on using an external MDA. The chapter on using an external MDA is a good example of why I like this book. Here is the full Table of Contents for the chapter:

1. Using MDA Programs with Postfix

1. What is a Mail Delivery Agent

1. Automatic Mail Filtering

1. Automatic Mail Replying

1. Automatic Program Initialization by Mail

1. Using an External MDA Program with Postfix

1. Configuring the main.cf file

1. Watching MDA Programs in the Postfix Log

1. The procmail MDA Program

1. Installing procmail

1. The procmail Command Line

1. User-Defined procmail Actions

1. Summary

In this chapter Blum gives a nice quick How-To on procmail. While it is not a full treatment of procmail it has enough information to download, compile, install, configure and run procmail. Coupled with the brief lessons on Unix, gcc, make and bash in the first section, an MS Exchange administrator on their first attempt in the Unix world is provided enough information to get procmail working as the MDA for their new Postfix MTA.

Section III covers advanced server topics including using MySQL, OpenLDAP and Majordomo with Postfix. Like the section on procmail, Blum covers installing and configuring each of these applications and how to make Postfix work with them. Chapter 20 covers POP3 and IMAP, which then leads nicely into the next chapter on SqWebMail. The final chapters are on performance tuning and troubleshooting.

Overall I have found this to be a well-written book that addressed several questions that I had about configuring and using Postfix (such as the SOHO section). It is clear, direct and covers each topic to a level that I found comfortable. For some people this book will be too advanced but that should not be anyone who has a working knowledge of mail servers or of Unix. I would recommend this book for someone who has started to use or wants to migrate to using Postfix.

My major complaint about this book is the price, $49.99. As much as I liked this book, 'Practical UNIX and Internet Security' was more densely packed with information and only cost $39.95.

Table of Contents

1. Introduction

Introduction to E-Mail Services and Postfix

1. E-Mail Services
2. Postfix Services
3. Server Requirements for Postfix
4. DNS and Postfix
5. SMTP and Postfix

Installing and Configuring Postfix

1. Installing Postfix
2. The master.cf Configuration File
3. The main.cf Configuration File
4. Postfix Lookup Tables
5. Using Postfix
6. Using Postfix as an ISP Mail Server
7. Using Postfix as an Office Mail Server
8. Postfix Server Administration
9. Migrating from Sendmail to Postfix
10. Using the Maildir Mailbox Format
11. Using MDA Programs with Postfix

Advanced Postfix Server Topics

1. Using MySQL with Postfix
2. Using OpenLDAP with Postfix
3. Using Majordomo with Postfix
4. Using POP3 and IMAP with Postfix
5. Using SqWebMail with Postfix
6. Performance Tuning Postfix
7. Common Postfix Problems

You can purchase this book at Fatbrain.

gempabumi asks: "I'm in the process of setting up a production server and I need to decide on an MTA. The main function of the MTA will be to run Mailman mailing lists. Of sendmail, Postfix, exim, and qmail, which MTA do you recommend? What are the strengths/weaknesses of each?"