Hello, thank you for all the replies. I've solved my current problem by going back to sendmail (which I'm better used than to postfix) and adding this line to the stock CentOS sendmail.mc: MASQUERADE_AS(`preferans.de')dnl Yes, I use Google Apps for incoming mail and that is why I have their MX servers. I also been using GMail and SMTP AUTH before - but I've removed that now, because I couldn't set the From or Reply-To header with that solution - Google was always rewriting it and thus it was bad for my Drupal site (users can't send mails to other users). Regards Alex