Virtual Domains and qmail

Here's a way to get control of your mail with secure, high performance and freely available software called qmail.
To Handle a Virtual Domain With an /etc/aliases-like File

If you have hundreds of users for a virtual domain, you can avoid the hundreds of .qmail-xxx files with a small script that calls qmail's forward command.

Instead of creating individual .qmail-xxx files in the virtual domain master user's home directory, create a single .qmail-default file containing the following line:

|/usr/local/bin/qmail_db_lookup /home/master/qmail_db

with /home/master/qmail_db modified to reflect the home directory of your virtual domain. You can then create (or adapt from your existing /etc/aliases) the file /home/master/qmail_db, consisting of lines with the virtual domain user, a colon and the forwarding address(es). The special user name “-” indicates where mail should be forwarded for any users not explicitly listed. If the “-” user name is not provided, mail for nonexistent users will be bounced. A sample qmail_db file might look like this:

-:  postmaster@somewhere.com
john.smith:   john.smith@alo.com
carl.jones:   cjones@test.net
karen.quincy: kquincy
all:  john.smith@alo.com cjones@test.net kquincy
Note the forwarding addresses for the “-” user must be an actual address; otherwise, mail to nonexistent addresses in the virtual domain will be accepted, but not delivered to anyone.

Listing 1

A more substantial package for supporting /etc/aliases, qmsmac, is available with qmail. qmsmac supports arbitrarily deep-nested aliases and long aliases but, like sendmail, requires you to rebuild a database of aliases every time your /etc/aliases file is changed.

Conclusions

qmail appears to be a speedy and robust replacement for sendmail. We've had qmail running on our Linux Internet server for many months now without a single glitch. The additional features provided by qmail could be useful to those of you hosting several virtual domains from a single Linux box, and the simpler configuration is an added bonus.

Mike Thomas is an Internet application developer working for a consulting firm in Saskatchewan, Canada. Mike lives in Massachusetts and uses two Linux systems to telecommute 2000 miles to his job and to graduate school at the University of Regina. He can be reached by e-mail at thomas@javanet.com.

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Qmail is good mail server daemon!

speedwayhke's picture

Qmail is good mail server daemon.It's easy configure than sendmail.especial in virtual domain.

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