I run my own mail server from colocation. I have so far refused to provide webmail because I can't find an implementation that isn't a constant stream of security holes, in exactly the way that Courier / Exim aren't.

Any recommendations? I won't use PHP or MySQL on grounds of taste and decency.

> I won't use PHP or MySQL on grounds of taste and decency.

Good for you.

http://roundcube.net/about

http://www.zimbra.com/

http://www.squirrelmail.org/

Are you being cheeky? At least 2 of those are PHP-based...