I've been sent here by the people at stackoverflow OK so I know I'm using the right code becuase I have it working on another server but when I try to send an email from a webpage on this particular server using php I get a success message back but the email never gets through. In /var/log/maillog I see Sep 11 14:20:28 ela1 postfix/smtp[11496]: CEE83E151FD: to=[My email address here], relay=none, delay=40, delays=0.08/0.01/40/0, dsn=4.4.3, status=deferred (Host or domain name not found. Name service error for name=btopenworld.co.uk type=MX: Host not found, try again) Can anyone help?