qmail + courier-imap

[Shango Oluwa]

Since you're still trying to get this configuration going, I want to
suggest that you consider an IMAP mailserver with the following
packages:

Postfix
Cyrus-IMAP
SASL encryption
MySQL 

(This setup will work without MySQL)

I have not done this myself in Ubuntu yet, but have got this working for
our organisation under another GNU/Linux distro. It works well and is
flexible. Especially postfix.

All that said, you might have specific reasons for using qmail...

Regards,
Shango