dear all, i have a puzzling problem.
first i will explain my network topoly.i have an exchange server 2003 in my lan.i have an ISA server.behind it there is a hardware firewall.between the ISA and the hardware firewall i have a mail filter server.my users are sendimg mails fine but in the pat week our purchasing department users complained that they are unable to send users to a specific company and they always get this error:
i tried to telnet on port 25 the specifeid MX but no response.
when i talked to them they said that they are reciving normally from other comapnies.
and what is weird is that they can send to us but we cannot send to them.
when i checked the log on the mailfilter i saw a failure message stating that :failed to connect to host (ip) and then the name of the domain.
does anyone has a clue how to solve this. ?thanks