CentOS 4.6
Webmin 1.390
Virtualmin 3.50
I was using sendmail.
I tried switching to postfix but now I get this error for each virtual server when validating virtual servers in virtualmin:
example.com
Mail for domain : The mail server is not configured to receive email for example.com
example is of course replaced with my real domain names in the errors.
What do I have to do to configure postfix so it can be used by the virtual servers?
Thanks!
Postfix uses a different virtual map file format, and if you created virtual servers in Virtualmin with Sendmail as the mail server, you will have to translate the virtual map file from sendmail into the format for Postfix. I don’t know of any automated tools for doing that. If you’re just starting and have no mail, and not very many virtual servers, I’d suggest just deleting your virtual servers and re-creating them. Obviously, if you have any data/mail/etc. in place, this isn’t an option, and you’ll need to translate the files.
The Postfix format looks like this:
virtualmin.com virtualmin.com
hostmaster@virtualmin.com virtualmin@virtualmin.com
joe@virtualmin.com joe.virtualmin
And you need at least the first line to convince Virtualmin that the mail server will accept mail for this domain, and then each mailbox needs and entry mapping to either another address or the username of the account holder.
Thanks for the fast response Joe!
That explains it 
I am still in test mode so the domains I have I can delete and recreate without too much hassle.