Hallo 2 all, since 3-4 weeks exists a problem with my postfix server under SuSE 10. One account recieves all incoming mails perfect. Only the sender recieves a mail that his mail is undeliverable. This is the Postfix program at host mail.brzen.de. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to <postmaster> If you do so, please include this problem report. You can delete your own text from the attached returned message. The Postfix program <email@example.com>: mail forwarding loop for firstname.lastname@example.org No aliases, no virtual users. All users exist in the linux system. All users except the user "support" have no the problem. The search in google has not helped.