So heres the problem, I have a client with Exchange 2003, and suddenly their mail is backing up in the queue, i disabled there McAfee A/V to make sure it wasnt blocking any ports, i cleared out the queue folder and still nothing, also i tried to telnet to the machine from outside the network and i got "could not open connection to host on port 25", but i did an smtp diag with mxtoolbox though and everything was good. I have noticed a few things though: They have lots of spam going on, The queue has stabilized to 196 (so i'm not sure if some mail is going through, while most wont...either that or people just gave up on sending mail lol) They have been blacklisted by two sites for spam Which leads me to another question...If i'm blacklisted on a few sites, would that mean all my mail would get rejected or just some?

You'll be blacklisted by any recipient who uses those lists for anti-spam checking. It sounds as if you are not doing any recpient filtering and not rejecting addresses that are not in your org. If would implement this at the server level if your anti-spam product doenst do this: http://support.microsoft.com/kb/823866 To create a recipient filter, follow these steps: Start Exchange System Manager. Expand Global Settings, right-click Message Delivery, and then click Properties. Click the Recipient Filtering tab. To filter e-mail based on a particular e-mail address, click Add, type the e-mail address, and then click OK. To filter messages that are directed to e-mail addresses that do not exist in your organization, click to select the Filter recipients who are not in the directory check box.

Ok thanks, but also what about my telnet session? usually when i open command prompt on my mail server, and i do telnet mydomain 25 i get a successful connection but when i do the same command (telnet theirdomain 25) on their mail server, i get connection denied. Any ideas? They arent publishing through TMG or ISA, they use a hardware firewall

Ok thanks, but also what about my telnet session? usually when i open command prompt on my mail server, and i do telnet mydomain 25 i get a successful connection but when i do the same command (telnet theirdomain 25) on their mail server, i get connection denied. Any ideas? They arent publishing through TMG or ISA, they use a hardware firewall IP restrictions or AV or protocol fitering perhaps. If you are their server locally, try telnetting to the localhost on port 25

Ok thanks, but also what about my telnet session? usually when i open command prompt on my mail server, and i do telnet mydomain 25 i get a successful connection but when i do the same command (telnet theirdomain 25) on their mail server, i get connection denied. Any ideas? They arent publishing through TMG or ISA, they use a hardware firewall IP restrictions or AV or protocol fitering perhaps. If you are their server locally, try telnetting to the localhost on port 25

Well i figured it out :) so basicly i went to the exchange machine and pinged 8.8.8.8, no response.. huh? opened IE, i have internet access, then it hit me, they are proxying through the another machine, but exchange has no actual internet access, so they finally double checked their firewall, lo and behold someone went messing around in the firewall profiles and moved the exchange associated profile. So once that was fixed, mail started pouring out of there =D. Thanks for all the help guys.

Well i figured it out :) so basicly i went to the exchange machine and pinged 8.8.8.8, no response.. huh? opened IE, i have internet access, then it hit me, they are proxying through the another machine, but exchange has no actual internet access, so they finally double checked their firewall, lo and behold someone went messing around in the firewall profiles and moved the exchange associated profile. So once that was fixed, mail started pouring out of there =D. Thanks for all the help guys.