postfix-ldap

Secure alternative to widely-used Sendmail (with OpenLDAP support)

Postfix attempts to be fast, easy to administer, and secure, while at the same time being sendmail compatible enough to not upset existing users. Thus, the outside has a sendmail-ish flavor, but the inside is completely different. Some features: Connection cache for SMTP, DSN status notifications, IP version 6, Plug-in support for multiple SASL implementations (Cyrus, Dovecot), TLS encryption and authentication, Configurable status notification message text, Access control per client/sender/recipient/etc, Content filter (built-in, external before queue, external after queue), Berkeley DB database, LDAP database, MySQL database, PostgreSQL database, Maildir and mailbox format, Virtual domains, VERP envelope return addresses and others.