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Info

The primary function of this check is to log in to an IMAP or POP3 mailbox to monitor whether or not the login is possible. An extended feature is that the check can fetch all (or just some) from the mailbox and forward them as events to the Event Console.

Status
colourGreen
titleLAST TESTED ON CHECKMK 2.2.0P1

Table of Contents

Step-by-step guide

  1. Setup → Services → HTTP, TCP, EMail, ... → Check Email → Add Rule

    • Service description

      • Here you can type in a service description. Please ensure this is unique per host and does not collide with other services.

    • Mail Receiving

      • You can select if you want to check your IMAP or POP3 login. It would be best to have your login credentials for your Email Mailbox.

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    • Forward emails as events to Event Console

      1. Forwarding Method

        • You can select if you want to send the events to the Event Console or a remote syslog host. If you want to send the events to the local EC, we recommend using the spooling mechanism.

          The check will store all collected events in one file in ~/var/mkeventd/spool using the spooling mechanism.

          Code Block
          languagebash
          themeRDark
          OMD[mysite]:~$ ll ~/var/mkeventd/spool/
          
          total 3600
          
          -rw-rw---- 1 mysite mysite 79124 Dec 7 15:36 mysite_407343_1607351778
          
          -rw-rw---- 1 mysite mysite 79124 Dec 7 15:37 mysite_408329_1607351841

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        • 
          


      1. Only process mails with matching subject

        • Use this option to not process all messages found in the inbox but only those whose subject matches the given regular expression. The text entered here is handled as a regular expression pattern. The pattern is matched from the beginning. Add a tailing $ to change it to a whole text match. The match is performed case-sensitive. Read more about regular expression matching in Checkmk in our official user guide.
          .

          • You need to be aware that a subject field could contain line breaks. This is depending on your mail client and mail gateway. You could check the raw email to find out how many line breaks you have.

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            .

          • Now you can use regex platforms like regex101.com to create a regex.

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            .

          • For advanced debugging
            .
              • Copy the plugin to the local path.

                Code Block
                languagebash
                themeRDark
                OMD[mysite]:~/lib/nagios/plugins$ cp check_mail ~/local/lib/nagios/plugins/

                .

              • Add a print for the subject.

                Code Block
                languagebash
                themeRDark
                     for index, msg in sorted(mails.items()):
                         subject = msg.get('Subject', 'None')
                         print(subject)

                .

              • Run the script manually.

                Code Block
                languagebash
                themeRDark
                OMD[mysite]:~/lib/nagios/plugins$ ./check_mail --pwstore=6@17@password_1 '--fetch-protocol=IMAP' '--fetch-server=imap.strato.de' '--fetch-tls' '--fetch-port=993' '--fetch-username=user@provider.com' '--fetch-password=*************' '--connect-timeout=10' '--forward-ec' '--match-subject=.*Incident.*\n.*assigned' 
                =?utf-8?Q?Incident_INC000000XXXX_has_bee?=
                 =?utf-8?Q?n_assigned_to_your_group_'XXXX=
                 =?utf-8?Q?XXXXX'_=XXXXX:_Comuni?=
                 =?utf-8?Q?XXXXX_-_Priority:_Low?=
                =?utf-8?Q?Incident_INC000000XXXX_has_bee?=
                 =?utf-8?Q?n_assigned_to_your_group_'XXXX=
                 =?utf-8?Q?XXXXX'_=XXXXX:_Comuni?=
                 =?utf-8?Q?XXXXX_-_Priority:_Low?=
                Forwarded 2 messages to event console | messages=2
                
                


      2. Events: Syslog facility

        • Use this syslog facility for all created events.

      3. Events: Hostname

        • Use this hostname for all created events instead of the mail server's name.

      4. Limit the length of the mail body.

        • When forwarding mail from the mailbox to the event console, the body of the mail is limited to the given number of characters.

      5. Cleanup messages

        • The handled messages (see subject matching) can be cleaned up by deleting them or moving them to a subfolder. By default, nothing is cleaned up.

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Debugging

Event Console Log

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