I transfered my website to my ubuntu 8.04 server, ISPCONFIG 2. I had some issues with smtp authentication through email clients but at least I could email from PHP scripts. I re-installed the server from scratch and now smtp works fine with email clients but no longer with PHP scripts! Here is my /var/log/mail.log Code: Jul 16 13:06:10 server1 postfix/pickup: 043F5195A3B3: uid=33 from=<www-data> Jul 16 13:06:10 server1 postfix/cleanup: 043F5195A3B3: message-id=<[email protected][email protected][email protected][email protected][email protected] In the log I found this: from=<[email protected] This is not the variable being passed as the FROM email address. Code: status=bounced (host mx.domain.com[220.127.116.11] said: 550 5.1.0 error: R4.1: 18.104.22.168 (in reply to MAIL FROM command)) I also made sure the FROM email alias existed on my server. Where does it get this weird email address from?