John Shepp :: Blog: Mail Server Hell!!

Yes fair reader, I did attempt the impossible, and in the process managed to create a few DNS nightmares in the process, nearly blowing this server off the grid in the process. The main reason for this exercise was to incorporate Squirrelmail and Majordomo

postfix The first step was to decide on a transfer method for the mail, and at first I just went with sendmail, which is common to most Linux distros. It uses the standard SMTP protocol to send and recieve mail on port 25. But, even though I have established an MX record pointing to it, it still would not accept mail for delievery. A few tutorials later, I opted to kill sendmail and use a more secure method, IMAP through dovecot and the front end would be Postfix . Postfix and Sendmail both have algorithms that allow you to masquerade a domain. It’s easier than setting up your box as the full domain it could be, with DNS to the max. Postfix just appends the proper METHOD headers to an outgoing message so that illegal entries like localhost.localdomain don’t prevent the message from being accepted. In the process of this exercise, I messed up my sendmail.mc and the resulting sendmail.cf files to the point where the binary doesn’t load anymore. Beware, if you plan to mess with these configuration files, back up the originals!

Another thing I tried was to make the box a different domain than the standard localhost.localdomain , but I realized that losing that functionality would cause grave consequences, as many programs depend on this interface. The CUPS server for example, has a web interface that uses it. As well as ColdFusion, and many other web applications. The /etc/hosts file has to have localhost.localdomain as one of it’s entries, but I tried also entering other zones, and the results were inconclusive. I tend to forget which step lead to the next and why I did it, just figuring out why it’s not working ends up being the focus. Now that it’s working, try sending me a message so I can at least test it? Thanks.

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