Hello. I have an Exchange 5.5 server that is working fine however about 2 weeks ago people in my company who use POP accounts from home started complaining that they could receive mail but could no longer send mail via the POP account. After doing some investigating I found out that it was only happening to people who had the same ISP from home. It turns out that the specific ISP shut down port 25 to all mail servers but there own. I guess this is becoming the new trend for ISP's to try and limit the amount of SPAM going thru their networks. I have recommended just using the ISP's mail server as the outgoing mail server and this seems to work fine. However the owner of my company felt the need to complain to the ISP who told him simply to add port 26 as an SMTP listener on the exchange server. I know what you all are going to say and I agree that this is a stupid solution but all of my arguements have been shot down and the owner wants me to do it. So my question is, how do I add a second SMTP listener on port 26 formy exchange 5.5 server? Just so you know, we use MS ISA 2000 as our firewall and it sits on the same box as the exchange server, and the exchange server is NOT published in the ISA server. Thanks in advance for your help!