Under certain circumstances the /var/ Volume becomes full due or utilizes a high amount of space due to message files created and retained in /var/spool/postfix/maildrop directory.
This issue has been observed in conjunction with scheduled cronjobs whose results generate message files to the /var/spool/postfix/maildrop directory. Cronjobs such as the required API Portal Sync or other custom scheduled cronjobs are examples of message files can be created in the aforementioned directory.
These files are retained in the maildrop folder due to the postfix service not running. If the postfix service is not running associated daemons such as 'pickup' and 'cleanup' are not actively parsing the maildrop directory to process and move these messages as required. This results in the backlog of message files in the maildrop directory and excessive space usage on the /var/ volume. More information about postfix is available below.
1. Start the postfix service:
postfix start
2. Verify the postfix service is running:
postfix status
3. Allow several moments for the postfix daemons to process the maildrop directory before reviewing the directory:
ls -lart /var/spool/postfix/maildrop
4. The maildrop directory should now contain no message files or only minimal amount of recently created message files.
More information about postfix is available in the postfix documentation.