Hello all, I've an exchange 2000 server and ISA on a separate server. I can receive Emails from the outside but can not send. It seems that my ISA doesnt accept to send. Here's my log : 192.168.2.12 : My Exchange Server Acces Echange : My rule which allow the following protocols for my exchange server : DNS Query; DNS Query Server; DNS Zone Transfer; SMTP; SMTP Server; SMTPS; SMTPS Server. I could not find the description of the value 20000, but it seems that my rule Acces Exchange is the problem. Any help is welcome 192.168.2.12, -, -, N, 2/28/2002, 8:44:46, fwsrv, UNI-FIREWALL, -, -, 164.128.76.39, 53, 60416, 0, 0, 53, UDP, UdpMap, -, -, -, 20000, -, Acces Exchange, -, 2, 28429 192.168.2.12, -, -, N, 2/28/2002, 8:44:46, fwsrv, UNI-FIREWALL, -, -, 164.128.36.34, 53, 61418, 0, 0, 53, UDP, UdpMap, -, -, -, 20000, -, Acces Exchange, -, 2, 28429 192.168.2.12, -, -, N, 2/28/2002, 8:44:46, fwsrv, UNI-FIREWALL, -, -, -, 0, 61418, 0, 0, 0, UDP, Bind, -, -, -, 20001, -, -, -, 2, 28429 Arnaud