Followed this guild here: http://www.howtoforge.com/virtual-users-domains-postfix-courier-mysql-squirrelmail-ubuntu8.10 After a bunch of fiddling I finally got it to internally all me to mail users that where in my DB [from my command line using mailx at least]. I can also log into the accounts via SquirrelMail. For some reason or another I can not mail outside of the the system or receive mails into the system. Either way you go it returns an error of: No Such User Here. So now I'm tearing my hair out, any thoughts?
Even more confusing, I can send and receive mails from my Yahoo account, but I several e-mails set up on some shared hosting over at HostGator. That's where these errors are happening.
Turns out its all about the server not properly authenticating, example here: Anyone know how to properly set it up?
Well, as it turns out I had the domain still attached to the shared hosting account after I changed it to point to the new server. After removing that it's all gravy!