We've got 2 postfix servers. One is a smtp server(server1) and the other is pop/imap server(server2). When I send a message to an unknow user the smtp server(server1) wants to send I bounce message back to me. The bounce message is send to the incoming mailserver(server2)which is correct. I don't recieve that message and when i look at the logs I see the following:
said: 554 5.7.1 This message has been blocked because the return email domain is invalid.(failed to obtain DNS record for domain ) (in reply to end of DATA command))
The return path is empty thats why I get this message. How can I prevent this?
Hope somebody can help me out.