Ok, please ignore me. Despite everything working just fine before using the php mail() form, and not after using it, postfix managed to disappear...
Oh, and I should mention, i can send emails through the php form if i send them to email address outside of of my server (ie hotmail.com emails)
After having some problems with ISPConfig mail, I reinstalled the lot on my dedicated server again today. The server name is:...
Separate names with a comma.