I have a Cisco 871, everything is owrking fine is firewall is disable, but when I enable it allowing HTTP, HTTPS, DNS, POP3 and SMTP (ANY<->ANY)I can only send emails to users in the same domain of the sender for the rest I receive "550 5.7.1 Unable to relay for xxxx@yyyy.com".
I changed the SMTP port in the Exchange side from 25 to 26 and I enableled the por 26 in the firewall and evething works fine.
Does Cisco IOS has a special configurationfor port 25 that I need to check?
Thanks!