outgoing mail does not work

[uji]

Hi,
I have Exchnage 5.5 sp3 . Last week, I can send and received mail to the internet. Unfortunately, today I noticed that we can received mail from internet but outgoing mail to the intrenet does not work.
I have stopped and start the IMC, and telnet proxy server ip add 25 and it gives response that the smtp is ready .And I did the same thing to the proxy server - telnet Exchnage server ip add 25 and it gives the similar result. the smtp connection is ready. Therefore I assume that the smtp connection between my Exchnage and proxy is working fine. And when we try to send the email to the internet, it doesn't give any Non Deliver Report.So we assume that the mail was actually sent to the receipent until I did the checking.
Can anyone advise me ..

thanks
uji

 

[Guest_imported]

I assume that you have checked the Event Viewer.

Have you check the \exchsrvr\imcdata\out folder to see if messages are piling up? Or, in Exch Admin, expand down to the connectors, open the IMS properties and check the Queues tab. You will at least know if they are making it out of your server. If they are piling up, in the IMS properties, click on the Diagnostic Logging tab and set the logging level to max in order to capture the SMTP session data in the Event Viewer.

If the messages are getting out of your server, then you have to go to the next machine in line toward the internet and keep going until you find out where they are getting chugged up. If there is not NDR, some machine somewhere is holding them (or throwing them away).

 

[Guest_imported]

Oh, one more thing, the really intense SMTP session logs are in \exchsrvr\imcdata\log.