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PRTG smtp notifications suddenly stopped working



Until recently mail notifications were functioning without a problem. It suddenly stopped working.

IP of the PRTG server is allowed to relay. I can telnet from the PRTG server to port 25 and send a message.

This is a log message from the mail server when it was working: 2013-06-30T09:11:39.057Z,MAIL\internal SMTP mail,............................,>,250 2.1.5 Recipient OK, 2013-06-30T09:11:39.057Z,MAIL\internal SMTP mail,............................<,DATA,

This is the log message since it stopped working: 2013-07-05T13:02:26.973Z,MAIL\internal SMTP mail,............................,>,250 2.1.5 Recipient OK, 2013-07-05T13:02:26.973Z,MAIL\internal SMTP mail,............................,-,,Remote

The change is in the last phase. Instead of DATA, the log is ,,Remote.

SMTP notifications were working just fine until recently, now nothing gets through. SMTP notifications from other systems that send e-mail to the same address (servers from the same and other network segments, backup job notifications, etc...) are delivered correctly.

exchange notifications smtp

Created on Jul 8, 2013 7:23:41 AM

3 Replies



Please update to version Then, please follow the guidelines outlined under How can I enable Notification Delivery Logging? Please forward us the generated log files to [email protected], with reference to this thread.

Created on Jul 11, 2013 12:04:10 PM by  Patrick Hutter [Paessler Support] (7,225) 3 3



This is the last part of the log wiht modified domain and username: Sent 7/11/2013 4:19:46 PM: RSET<EOL> Recv 7/11/2013 4:19:51 PM: 250 2.0.0 Resetting<EOL> Sent 7/11/2013 4:19:51 PM: MAIL FROM: <[email protected]><EOL> Recv 7/11/2013 4:19:51 PM: 250 2.1.0 Sender OK<EOL> Sent 7/11/2013 4:19:51 PM: RCPT TO:<[email protected]><EOL> Error sending "Email": Read timed out.

Created on Jul 11, 2013 2:24:36 PM



From what we can discern in the log files provided this seems to be a tarpitting / blacklis issue. If you try using a different sender / recipient, does that work? Please also check the server settings. Beyond that, if you try using a SMTP sensor with the same settings, does it work?

Created on Jul 15, 2013 11:03:20 AM by  Patrick Hutter [Paessler Support] (7,225) 3 3

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.