MiniG is a webmail written as an alternative to IMP for groupware solution like Blue Mind. MiniG interface uses google web toolkit to provide a full ajax interface similar to GMail.
Blue Mind is an open source alternative to exchange based on postfix, cyrus imap.
Openmailadmin is a administration interface to every complete IMAP mailserver daemon. It supports every feature IMAP provides, and fits in most MTA configurations. A key feature is the non-standard, generic administration hierarchy.
Active Directory/LDAP Connection
Multiple SMTP instances
Can Act as PDC
Active Directory/LDAP connection