Getting sendmail Up and Running

sendmail is powerful, but at times it appears complicated too. Unravel the sendmail knot and you can configure this awesome mail server on your Mac OS X system.

sendmail is complicated software, no doubt about it. But sendmail is also the Swiss Army Knife of mail servers, and I don’t mean one of those little keychain trinkets. Instead, it’s the monster three-inch-wide kind with all the tools, most of which you have never seen before and have no idea what they do. However, with a little time and patience, you too can become proficient enough with sendmail to make it accomplish everything you need.

Here’s what I’ll cover in this hack:

  • Dealing with Jaguar’s permissions and sendmail’s security precautions

  • Working with configuration files


  • How to set up aliases

  • How to allow relaying from certain hosts

  • Running behind a firewall

  • Working with lame ISPs

Be warned, this is not a beginner’s article. If you’re uncomfortable performing shell commands as root on your system with sudo [Hack #50] and editing special Unix files [Hack #51], you may want to acquaint yourself with these first. However, if you do have a bit of shell experience, and I haven’t scared you off by mentioning the word pico, then this should be just the quick reference you need to get your own mail server running under OS X.

Hacking the hostconfig File

First, we’ll need to edit the MAILSERVER line in /etc/hostconfig so that sendmail starts automatically:

% sudo pico /etc/hostconfig ...

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