What email server software should I use?

What open source email server software do you recommend for private use on a Linux server?

Judging from this comparison, Kolab, Apache_James and Citadel looks like the best alternatives.

I don't care about having a web interface but I guess it's a nice bonus.

I want something that is stable, reliable and requires little maintenance, security is of course also important.

Kolab is pretty cool and has Owncloud plugins.

Thank's for answering, it leans towards towards Kolab, will probably check it out!

This is what I use, http://flurdy.com/docs/postfix/