Hi, > We are not gettting any NDR but the theres a lot of Queue growth and i > am also not able to telnet to port 25 from an external Ip thanks Gautam That's not a good sign, if you are unable to telnet to the mailserver's port 25 from outside. How about the mailserver's IP address port 25? If neither works, you have a firewall issue or Exchange is not running. If IP works but domain name does not, it's possibly a DNS problem. Also: from the console of the exchange server, in a MS DOS Command window, are you able to telnet to port 25 of an external mailserver (Exchange or otherwise)? be sure you test a mailserver FQDN, not just the base domain name. To find the mailserver of a given domain name, you can check for the MX records at http://www.dnsstuff.com/ best regards Mike Salim.