E-Mail Server Setup Advice?

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?"

Comments

Dear Slashdot

[Mensa Babe]

Please do my work for me.
Sincerely, Slashdot reader.

Roll your own for full job security...

[jonadab]

Hey, you want job security, right?

Write your own mail server software, preferably in an unpleasantly horrible language, such as Threaded Intercal. Make sure it keeps all the mail and account information in something inherntly tied to the implementation language, such as stored procedures, disk-based monads, persistent lexical closures, or the like.

Did I mention the part about not supporting POP3 or IMAP, but rolling your own protocol and client? You wouldn't want some hotshot hiree coming along, extracting all the mail that easily, and moving the company over to Exim or Postfix.

Oh, and you want there to be a lot of resistence to moving away from your solution, so make it do something executives will like, such as have the server authenticate clients by MAC address so they don't have to have passwords.

Also, just to raise the bar for potential replacement systems, roll in some features that have nothing whatsoever to do with mail. For instance, you could tie the mail server into the company accounting system and put user interface in the client for viewing up-to-the-minute charts showing revenues, remaining fund levels in various funds, and so forth. Arrange it so that users can send each other these charts (actually just magic tokens that pull them up) by email.