Article ID: 5811, created on Nov 28, 2008, last review on Aug 12, 2014

  • Applies to:
  • Plesk 9.x for Linux/Unix


It is Parallels Plesk Panel version 9 installed in Virtuozzo Container. 
Message Transfer Agents (MTA) Postfix takes too much resources. privvmpages and numothersock reached their limits, and so mail service works unstable.


By default Postfix has big maximum number(100) of parent SMTP processes: delivering, filtering and other setting-up actions. Mail hangs and resources reach their limits if outgoing email messages cannot be delivered due to one of setting-up action above.

Use environment variable postconf to decrease maximum number of parent SMTP processes.

~# postconf -e 'default_process_limit=20'

Also it is recommended to disable unused services like ifmail and uucp in Postfix configuration /etc/postfix/ (/usr/local/etc/postfix/ for FreeBSD).

And reload MTA configuration with mailmng:

~# PRODUCT_ROOT_D/admin/sbin/mailmng --reload-service
Reloading postfix: [  OK  ]

Additional information

Use the following article to get value of PRODUCT_ROOT_D for your system:

6ef0db7f1685482449634a455d77d3f4 a914db3fdc7a53ddcfd1b2db8f5a1b9c 29d1e90fd304f01e6420fbe60f66f838 56797cefb1efc9130f7c48a7d1db0f0c

Email subscription for changes to this article
Save as PDF