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PRTG smtp notifications suddenly stopped working



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 [],
250-SIZE 10485760,
250 XEXCH50,
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

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.

exchange-2007 prtg smtp

Created on Sep 1, 2010 3:14:07 PM

Last change on Sep 3, 2010 11:23:36 AM by  Torsten Lindner [Paessler Support]

3 Replies



Dear Tim,

do SMTP Sensors or Roundtrip Sensors work on your Exchange Server?

Created on Sep 3, 2010 12:10:15 PM by  Torsten Lindner [Paessler Support]



I will have to set one up and see. not something I'm currently using.

Created on Sep 3, 2010 1:35:37 PM



SMTP/POP3 roundtrip sensor fails with Sending Mail: Read Timeout.

I also see this in the SMTP logs after the 250 2.0.0 Resetting,

451 4.7.0 Timeout waiting for client input,

Used WireShark to capture packets and it show the same thing. PRTG connects, EHLO looks good, RSET command is issued, server responds with Resetting, then nothing. It almost appears that PRTG is expecting a response other than 250 2.0.0 Resetting, and therefore does not proceed sending commands.

Created on Sep 3, 2010 3:50:36 PM

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