Postfix question with smtp relay
I have two centos 5.2 built. One on isp that does not block port 25 in/out. And one on isp that does. So i thought, i would use that smtp for the one that does not block 25 so i followed the relaying to isp's smtp server howto on this site. So now,when i look at the maillog it looks like this:
mx00.mail.server.net[18.104.22.168]: No route to host (port 25). Now, the Port 25 does jump out in this message but more than that is the "no route to host". What does this mean?