Configuration of Qmail
Qmail is similar to postfix in that it was designed as a sendmail replacement and is a collection of smaller programs instead of one large one. The design goal behind Qmail is security, so often the smaller programs will run as lower-privileged users. Some of the more common Qmail programs are listed in Table 17-2.
Listens for incoming TCP connections and hands them off to the appropriate program. Similar to inetd or xinetd.
Handles incoming email.
Injects outgoing email into the mail queue.
Delivers mail messages currently in the queue.
Formats mail correctly and places it in the queue for delivery.
Invokes qmail-local to handle local delivery.
Invokes qmail-remote to handle remote delivery.
Delivers email locally.
Delivers email remotely.
Receives mail via the Quick Mail Queueing Protocol and invokes qmail-queue to put mail in the outgoing queue.
Summarizes the current contents of the mail queue.
Lists messages and recipients of emails in the outgoing queue.
Lists hosts that have timed out on mail delivery attempts.
Clears the host timeout list.
Analyzes the current qmail configuration files and explains the setup.
A wrapper program that starts qmail-send, qmail-lspawn, qmail-rspawn, and qmail-clean with the appropriate user IDs so mail delivery ...