Hi I live in Denmark, where we have got an ISP, who blocks for incomming port 25 to their customers. This is for preventing open relays. Okay, I can make a closed relay, and I do not use them as my own ISP, so I don't really care for that. They have "solved" the problem in the way, that the ISP has a backup MX, which is the only MX in the world who can talk to the customers mail server. So for your domain, i make: domain.dk. IN MX 10 mail.domain.dk. domain.dk. IN MX 10 backup-mx.isp.dk. And it works But my problem is that when my own mailserver tries to deliver a mail to a mailserver by a customer, a router in another ip than the customer sends me that ICMP packet. That packet is obviosly not RELATED, and the conection tracking does not send that ICMP packet back to my mailserver which initially started the failing connection. The packet can be seen here: http://home.ballbreaker.dk/phpstat/id.php?id=614279 So what do I do now ? Rgds, Jesper Lund
