The latest stable version of Postfix is 2.7, the version included with Webmin is 2.3.3 (from 2006?). Are there any plans to upgrade this?
Virtualmin doesn't provide Postfix -- the majority of the packages in use on your server are provided by your distro, and Postfix is one of those.
CentOS 5.x is one of the distros that provides Postfix 2.3.3 with it. One thing to remember about CentOS is that they backport security fixes and such from current versions to the version they ship.
Oh, that makes sense then.
Thanks for the quick response.