That did the trick. Make sure auto_create_user is set to “TRUE” in PATH_TO_ROUNDCUBE/config/ main.inc.php, and then in your Apache Website settings, put the URL to the installation of roundcube and it does the trick
I’m going to lay it out real quick here and hope that someone can use this info
Create a virtual service for your webmail, let’s call it “mail.domain.tld” (which will create a /home/mail directory.)
Install RoundCube in /home/mail/public_html
Configure your RoundCube install, MAKING SURE that auto_create_user is set to “TRUE” (this is in config/main.inc.php)
Log onto VirtualMin as your superuser account
go to System Settings -> Server Temlpates -> Default (or the template you want to change) and use the dropdown box to select “Apache Webserver”
On the Apache Webserver Config page, change the radio box under URL for webmail redirect to the second one (text box) and enter the absolute url to the webmail installation (in our case, http://mail.domain.tld)
THIS IS IMPORTANT (This is what messed me up) Leave the Redirect webmail.domain to Usermin radio box to YES. I don’t know why, but for some reason, if you make it No, your Roundcube Installation will NOT work
Save
Done
Now, whenever your clients want to access webmail, they go to webmail.theirdomain.tld and it will redirect to the webmail.domain.tld alias you set up. They log in with their login information and presto! It’s working
One thing I did was to change the username format to login@domain. Most people are used to doing things that way, and it makes it easier. There are proabably about 50 different schools of thought on this option, so weigh your choices before you make that decision.
Hope this helps