i’m administrating varius mail servers for our clients and on some of them i experienced a problem of sendig mail to certain domains. Messages for some domains remains into the quees with this message “The semaphore timeout period has expired”. So i tried to telnet to one of this domain and i was soprised. I was unable to connect via telnet on port 25 to those servers. So i checked up if i can connect to those serves directly from the router and i did it. I think its a problem on firewall Watchguard X500 but its not under my menagments so i don’t know what can be. On Cisco PIX firewalls there was a command fixup dns 512 that make similar problems. Somebody had similar experience?