We have had SMTP notifications working just fine until the end of July when patched our Exchange Server to SP1 Upate Rollup 10. Since then the SMTP notifications are not being delivered. The PRTG Logs says "Error sending 'Email': Connection Closed Gracefully". SMTP logs on the Exchange server show this (hostnames and IPs changed for privacy):
"220 exch.domain.local Microsoft ESMTP MAIL Service ready at Wed, 1 Sep 2010 10:55:40 -0400", EHLO prtg.domain.local, 250-exch.domain.local Hello [192.168.32.30], 250-SIZE 10485760, 250-PIPELINING, 250-DSN, 250-ENHANCEDSTATUSCODES, 250-AUTH, 250-8BITMIME, 250-BINARYMIME, 250-CHUNKING, 250 XEXCH50, RSET, 250 2.0.0 Resetting,
IP of the PRTG server is allowed to relay. I can telnet from the PRTG server to port 25 and send a message.
Have upgraded PRTG Network Monitor to 220.127.116.1102
To reiterate. SMTP notifications were working just fine until recently, now nothing gets through. Other systems that send e-mail to the same address (printers/copiers, backup job notifications) are delivered correctly.