Hi, Jim Well, I'm back... Looks like something else is still wrong. Here are some more details. My ISA is having two IPs assigned: 193.231.227.162 and .163. .162 is the default IP address. On each I have assigned a different domain name: 162 = domain1 and 163 = domain2. ISA Server is visible outside with the first IP, the one with .162. The name server, as per my DNS setting and as per my registrator, is on the .163 IP. Mail server is serving for domain2. Our company wants a second mail server for domain1, which will be published thru .162. I've made all the settings as instructed, but emails still can't get thru. If nslookup with packet filter enabled, everything's OK: I get all the records from my DNS. I have 2 mail server publishing rules, one for each external NIC and both rules are redirecting SMTP traffic to the same Exchange server. Also, I have a packet filter allowing SMTP packets on both direction, on default external IP. What have I done wrong ? What I have to change in order to have 2 exchange servers published thru this ISA Server ? TIA Alin