What is this?

This knowledgebase contains questions and answers about PRTG Network Monitor and network monitoring in general.

Learn more

PRTG Network Monitor

Intuitive to Use. Easy to manage.
More than 500,000 users rely on Paessler PRTG every day. Find out how you can reduce cost, increase QoS and ease planning, as well.

Free Download

Top Tags

View all Tags

IMAP subject detection



The IMAP probe does not detect mail with the following subject (in french) : "État OK".

Below is the log of the probe. Additional information: the logs show that the probe correctly detects the object of other emails

Sensor LOG :

Processing Mail: 158
Sent 10/05/2021 14:38:37: C5 FETCH 158 (BODY.PEEK[])<EOL>
Recv 10/05/2021 14:38:37: * 158 FETCH (BODY[] {29517}<EOL>
Received: from XXXXXXXXXX.eurprd03.prod.outlook.com (2603:10a6:10 ... ="11"></td
Recv 10/05/2021 14:38:37: ><EOL>
	<tr height=""><td>&nbsp;</td></tr><EOL>
	 ... <EOL>
Recv 10/05/2021 14:38:37: )<EOL>
C5 OK FETCH completed.<EOL>
Sender: [email protected]
Timestamp: 10/05/2021 07:19:53
Message age: 7 hours
Subject did not match filter.

imap snmp subject

Created on May 10, 2021 12:53:25 PM

Last change on May 10, 2021 5:07:07 PM by  Felix Wiesneth [Paessler Support]

3 Replies




According to the log file that you have shared the "Subject" of the email is empty and as such does not match the set filter. Please check again the emails that you want to monitor, and the filter settings of the IMAP sensor.

Kind regards,
Sasa Ignjatovic, Tech Support Team

Created on May 12, 2021 9:50:23 AM by  Sasa Ignjatovic [Paessler Support]



Hello, thank you for looking at my case.

The Subject is seen as empty in the logs.

But in reality he is not.

Below is the same email seen by an email client

Sender  : [email protected]
Sent : lundi 10 mai 2021 07:20
To : XXXXXX Notifications <[email protected]>
Subject : Rapport de Sauvegarde du 09/05/2021 : État OK

Created on May 12, 2021 11:05:07 AM




In this case I would recommend that you open a support ticket so that we can further investigate the issue. You can open a support ticket from the PRTG web interface by going to Setup>Contact Support, or by sending us a email at [email protected].

Kind regards,
Sasa Ignjatovic, Tech Support Team

Created on May 14, 2021 12:57:50 PM by  Sasa Ignjatovic [Paessler Support]

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.