I installed Virtualmin using their free GPL'd install script on a fresh install of CentOS5.
Currently, this server all it needs to do is serve http and send out signup/confirmation/activation emails generated by PHP scripts.
So, using Virtualmin, I added a virtual server called domain.com. Domain.com has http being served, ftp, mysql is also working, but mail is being a problem. Virtualmin installs Postfix as the mailer.
domain.com's email is being handled by GoDaddy. But I just want the scripts to be able to send out all the generated emails from the CentOS server/postfix.
For example, the domain's admin should be able to send out whatever email addr he wants:
I want it to go out like email@example.com
, instead of firstname.lastname@example.org
I tested it out, I sent emails using Usermin to @msn (failed 4 out of 6 times), @gmail (all success), @domain1 and @domain2 (handled by GoDaddy's email again, where all was successful to go to @domain1, but 100% failure on @domain2)
The custom domains have no spam/junk controls.
Now, if I want the emails to go with 99% success rate, what do I need to change in postfix configuration?
Please, please help.