The qmail Handbook

qmail supports forwarding and mailing lists:

• Sendmail .forward compatibility. Using the dot-forward package, Sendmail-style .forward files can be used.

• Hashed forwarding databases. The fastforward package implements a high-performance forwarding database.

• Sendmail /etc/aliases compatibility. The fastforward package includes a clone of the newaliases command that supports Sendmail-style alias databases.

• Address wildcards. Using .qmail-default, .qmail-something-default, and so on, users and mail administrators can specify the disposition of messages to multiple addresses.

• Mailing-list owners. If a message is forwarded to .qmail-something, and .qmail-something-owner exists, it automatically gets a return address of user-something-owner@domain. This diverts bounces and vacation messages from going to the sender.

• Variable Envelope Return Path (VERP) support. VERP allows reliable automatic recipient identification for mailing-list bounces.

• Delivered-To header field. Each "final" delivery causes the addition of a Delivered-To header field containing the recipient address. If a message already contains a Delivered-To for the current recipient, the message is rejected. This enables automatic loop prevention, even across hosts.

• Automatic subscription management. The ezmlm package allows users to subscribe and unsubscribe themselves from mailing lists. It also tracks bounces and removes invalid addresses.