When sending emails with PHP, (from looking at the logs) the from address is translated to 'webIDfirstname.lastname@example.org. But when the email is delivered, the from address looks correct ([email protected]). So here is the example from my log: amavis: (02564-02) Passed CLEAN, <[email protected]> -> <[email protected]>, Message-ID: <[email protected]> So the server domain is not the same as the website sending the email. I can't even see a reference of the actual domain. some mail servers will not accept emails like this. said: 550-Verification failed for <[email protected]> 550-The mail server could not deliver mail to [email protected]domain But if it did a verification on the actual sender domain, it would be fine. When using Outlook, it does not do this. The address is correct, even when looking at the log. I had the same thing with ISPconfig2, just cant figure out what it is. Any help would be much appreciated.