Virtualmin with Virtual Mail users


My server is setup with Virtualmin, Postfix and Dovecot.

Postfix and Dovecot are setup as follow, to manage mail users as Virtual Mail users.

The reason for doing this was that with the UNIX User setup for Mail users we had too many Unix users,
this caused the server to use up too much memory.

My questions are as follow:

  1. How would we go about having Virtualmin manage these Virtual Mail users. Create, remove, change passwords, etc.
  2. How would we go about having Usermin use the Virtual Mail user setup (virtual passw and shadow file) for authentication so that users would be able to use Usermin to read their mail online.
  3. Would Virtualmin be able to run with this setup or is the UNIX user setup the only way to go? And if so how would I go about using the UNIX user setup so that it does not use up too much mem.

Would appreciate any advice and comments from people who have gone the route in the past or anyone who would be able to pass on some advice.



The Postfix module for Virtualmin is tied to using system users – be it /etc/passwd, LDAP, or so.

Could it work? Maybe, with some significant changes; but it wouldn’t be simple, and you’d probably need to recode the Virtualmin Postfix module :slight_smile:

How many mail users is it that you’re looking to have on your server?

The memory issues of how mail is handled isn’t so much an issue with it having to read user and password information from the password file. Memory is used up by having to run things like SpamAssassin, ClamAV, and other high memory apps for processing individual email.

If memory is a concern, one way to handle that is to put SpamAssassin and ClamAV on another server – one dedicated for just running those daemons. You may want to look at this document:,spam_and_virus_scanning/

Scroll to the bottom, and check out the sections labeled “Configuring Virtualmin to Use a Remote Spamd” and “Configuring Virtualmin to Use a Remote Clamd”.