Forum OpenACS Q&A: Response to OT: imap server recommendation

If you're looking for a scalable answer:
  CerritosLUG Qmail-LDAP Tutorial

That's just the backend. For the front-end, run something like Imp or SquirrelMail (both are php being run under Apache). Both have their strong points. Imp is a little bit more mature, but SquirrelMail has a good feel to it.

Feel free to reply to me at my work address if you would like more details.

Regards... Todd