you could try horde - it's pretty full-featured. Mta, i would recommend qmail, but YMMV... The setup will be pretty tedious if u go this way, but once setup, everything will run very nicely.-jf
Horde/IMP from OpenBSD ports seems to have a problem. The attachment size, mime type and name is reported correctly in IMP, but when I download it, their size is 0KB. you can read about it in horde.imp group. I had to change to squirrelmail FBN
