Overview

This check monitors the size of all your Postfix queues.

Setup

Installation

The Postfix check is included in the Datadog Agent package, so you don’t need to install anything else on your Postfix servers.

Configuration

This check can be configured to use the find command. This requires granting sudo access to the dd-agent to get a count of messages in the incoming, active, and deferred mail queues.

Optionally, you can configure the Agent to use a built in postqueue -p command to get a count of messages in the active, hold, and deferred mail queues. postqueue is executed with set group ID privileges without the need for sudo.

WARNING: Using postqueue to monitor the mail queues doesn’t report a count of messages for the incoming queue.

Metric collection

Using sudo

1. Edit the file postfix.d/conf.yaml, in the conf.d/ folder at the root of your Agent’s configuration directory. See the sample postfix.d/conf.yaml for all available configuration options:

   init_config:
     ## @param postfix_user - string - required
     ## The user running dd-agent must have passwordless sudo access for the find
     ## command to run the postfix check.  Here's an example:
     ## example /etc/sudoers entry:
     ##   dd-agent ALL=(postfix) NOPASSWD:/usr/bin/find /var/spool/postfix/incoming -type f
     ##
     ## Redhat/CentOS/Amazon Linux flavours need to add:
     ##          Defaults:dd-agent !requiretty
     #
     postfix_user: postfix
   
   instances:
     ## @param directory - string - optional - default: /var/spool/postfix
     ## Path to the postfix directory. The directory option is required if `postqueue: false` is set. For more 
     ## information see https://docs.datadoghq.com/integrations/postfix/#using-sudo.
     #
     - directory: /var/spool/postfix
   
       ## @param queues - list of string - required
       ## List of queues to monitor.
       #
       queues:
         - incoming
         - active
         - deferred
   

2. For each mail queue in queues, the Agent forks a find on its directory. It uses sudo to do this with the privileges of the Postfix user, so you must add the following lines to /etc/sudoers for the Agent’s user, dd-agent, assuming Postfix runs as postfix:

   dd-agent ALL=(postfix) NOPASSWD:/usr/bin/find /var/spool/postfix/incoming -type f
   dd-agent ALL=(postfix) NOPASSWD:/usr/bin/find /var/spool/postfix/active -type f
   dd-agent ALL=(postfix) NOPASSWD:/usr/bin/find /var/spool/postfix/deferred -type f
   

3. Restart the Agent

Using postqueue

1. Edit the postfix.d/conf.yaml file, in the conf.d/ folder at the root of your Agent’s configuration directory:

   init_config:
     ## @param postqueue - boolean - optional - default: false
     ## Set `postqueue: true` to gather mail queue counts using `postqueue -p`
     ## without the use of sudo. Postqueue binary is ran with set-group ID privileges,
     ## so that it can connect to Postfix daemon processes.
     ## Only `tags` keys are used from `instances` definition.
     ## Postfix has internal access controls that limit activities on the mail queue.
     ## By default, Postfix allows `anyone` to view the queue. On production systems
     ## where the Postfix installation may be configured with stricter access controls,
     ## you may need to grant the dd-agent user access to view the mail queue.
     ##
     ## postconf -e "authorized_mailq_users = dd-agent"
     ##
     ## http://www.postfix.org/postqueue.1.html
     ##
     ## authorized_mailq_users (static:anyone)
     ## List of users who are authorized to view the queue.
     #
     postqueue: true
   
   instances:
     ## @param config_directory - string - optional
     ## The config_directory option only applies when `postqueue: true`.
     ## The config_directory is the location of the Postfix configuration directory
     ## where main.cf lives.
     #
     - config_directory: /etc/postfix
   
       ## @param queues - list of string - required
       ## List of queues to monitor.
       #
       queues:
         - incoming
         - active
         - deferred
   

2. For each config_directory in instances, the Agent forks a postqueue -c for the Postfix configuration directory. Postfix has internal access controls that limit activities on the mail queue. By default, Postfix allows anyone to view the queue. On production systems where the Postfix installation may be configured with stricter access controls, you may need to grant the dd-agent user access to view the mail queue. See the postqueue Postfix documentation for more details.

   postconf -e "authorized_mailq_users = dd-agent"
   

   List of users who are authorized to view the queue:

   authorized_mailq_users (static:anyone)
   

3. Restart the Agent.

Log collection

Available for Agent versions >6.0

Postfix sends logs to the syslog daemon, which then writes logs to the file system. The naming convention and log file destinations are configurable:

/etc/syslog.conf:
    mail.err                                    /dev/console
    mail.debug                                  /var/log/mail.log

1. Collecting logs is disabled by default in the Datadog Agent, enable it in your datadog.yaml file:

   logs_enabled: true
   

2. Add the following configuration block to your postfix.d/conf.yaml file. Change the path and service parameter values based on your environment. See the sample postfix.d/conf.yaml for all available configuration options.

   logs:
     - type: file
       path: /var/log/mail.log
       source: postfix
       service: myapp
   

3. Restart the Agent.

Validation

Run the Agent’s status subcommand and look for postfix under the Checks section.

Data Collected

Metrics

Events

The Postfix check does not include any events.

Service Checks

The Postfix check does not include any service checks.

Troubleshooting

Need help? Contact Datadog support.

Further Reading

Additional helpful documentation, links, and articles:

• Monitor Postfix queue performance