Basically to cut a long story short I spent hours reading through fixes (old and new) trying to gauge where the issue was. I replaced lines of code, and repeated test after test purchase without luck. I even installed Open Cart from scratch hoping I had messed something up, but still no dice. The mail function was not working, but not giving any error messages, whilst the SMTP function was giving a timeout error.
However once I changed the SMTP host from "mail.myserver.com" to "localhost" the mail started working correctly. Not saying this is Open Cart's issue, and I could have missed something easy in the forums, but I did spend hours trying things like IP addresses and playing with the server config. The PHP mail function still does not work, but not that worried now that I have settings that work correctly
