# Postfix Input Plugin

The postfix plugin reports metrics on the postfix queues.

For each of the active, hold, incoming, maildrop, and deferred queues
(<http://www.postfix.org/QSHAPE_README.html#queues>), it will report the queue
length (number of items), size (bytes used by items), and age (age of oldest
item in seconds).

## Configuration

```toml
# Measure postfix queue statistics
[[inputs.postfix]]
  ## Postfix queue directory. If not provided, telegraf will try to use
  ## 'postconf -h queue_directory' to determine it.
  # queue_directory = "/var/spool/postfix"
```

### Permissions

Telegraf will need read access to the files in the queue directory.  You may
need to alter the permissions of these directories to provide access to the
telegraf user.

This can be setup either using standard unix permissions or with Posix ACLs,
you will only need to use one method:

Unix permissions:

```sh
sudo chgrp -R telegraf /var/spool/postfix/{active,hold,incoming,deferred}
sudo chmod -R g+rXs /var/spool/postfix/{active,hold,incoming,deferred}
sudo usermod -a -G postdrop telegraf
sudo chmod g+r /var/spool/postfix/maildrop
```

Posix ACL:

```sh
sudo setfacl -Rm g:telegraf:rX /var/spool/postfix/
sudo setfacl -dm g:telegraf:rX /var/spool/postfix/
```

## Metrics

- postfix_queue
  - tags:
    - queue
  - fields:
    - length (integer)
    - size (integer, bytes)
    - age (integer, seconds)

## Example Output

```shell
postfix_queue,queue=active length=3,size=12345,age=9
postfix_queue,queue=hold length=0,size=0,age=0
postfix_queue,queue=maildrop length=1,size=2000,age=2
postfix_queue,queue=incoming length=1,size=1020,age=0
postfix_queue,queue=deferred length=400,size=76543210,age=3600
```
