SMTP 25 blocked externally

Posted by Jeff on Server Fault See other posts from Server Fault or by Jeff
Published on 2011-01-08T16:02:39Z Indexed on 2011/01/08 16:55 UTC
Read the original article Hit count: 142

not sure how to title this question...

we run an exchange server with around 80 internal users, all outgoing mail is relayed off a smart host (ISP smtp server) so nothing is actually sent to the world via our server. i wanted to check the server, locally i can telnet to port 25 with no issues and receive the esmtp service ready reply. whenever i do it from an external address (off our local network) i receive unable to connect error 10060.

can this cause problems with SPF records, and reverse DNS ? should my exchange server be able to accept smtp requests, requiring authentication before i am able to send from external addresses? if so how...

also the exchange server is behind a NAT (asa) device, more than likely thinking that the nat is not configured to route the smtp 25 request to the exchange server..

thanks

© Server Fault or respective owner

Related posts about windows-server-2008

Related posts about networking