Article ID: 114276, created on Jul 3, 2012, last review on Aug 12, 2014

  • Applies to:
  • Plesk 10.x for Linux

Release Notes

The issue has been fixed since Plesk 11.0 MU#7.


Messages cannot be delivered from Parallels Plesk Panel servers to certain mail servers. Messages are stuck in the mail queue, and the following error can be found in the /usr/local/psa/var/log/maillog log file:

Jul  2 11:48:11 vps281cloud qmail-remote-handlers[13595]: from=mail@domain.tld
Jul  2 11:48:11 vps281cloud qmail-remote-handlers[13595]: to=mail@anotherdomain.tld
Jul  2 11:48:21 vps281cloud qmail: 1341222501.493270 delivery 5: deferral: System_resources_temporarily_unavailable._(#4.3.0)/
Jul  2 11:48:21 vps281cloud qmail: 1341222501.493359 status: local 0/10 remote 1/20
Jul  2 11:48:21 vps281cloud qmail: 1341222501.493770 delivery 4: deferral: System_resources_temporarily_unavailable._(#4.3.0)/

The issue occurs when qmail is used as the MTA (Message Transfer Agent), and there are no IPv6 addresses assigned on the server.


There are several possible solutions for this issue, presented in the recommended order. Choose the most suitable:

1. (Recommended) Switch the MTA from qmail to Postfix. Refer to the following article for instructions:

#5801 How to define which MTA is used in Parallels Plesk Panel, and how to switch from Qmail to Postfix and back

2. Configure the IPv6 address on the server.

3. Replace /var/qmail/bin/qmail-remote with the file from the attachment using the following instructions:

  1. Download the attached archive. It contains a fixed version for different operating systems and architectures.
    # wget
  2. Extract files from the archive:
    # tar -zxvf qmail-remote.tar.gz
  3. Back up the original /var/qmail/bin/qmail-remote.moved file:
    # mv /var/qmail/bin/qmail-remote.moved{,.orig}
  4. Replace it with the one from the downloaded archive, according to your operating system and architecture. Archive contains file qmail-remote, rename it to /var/qmail/bin/qmail-remote.moved:
    # cp /root/qmail-remote /var/qmail/bin/qmail-remote.moved
    # chmod 555 /var/qmail/bin/qmail-remote.moved
    # chown root:qmail /var/qmail/bin/qmail-remote.moved
  5. Restart qmail service:
    # service qmail restart
    Stopping : Starting qmail:                                 [  OK  ]
Note: If you apply this solution, it is important to check whether the /var/qmail/bin/qmail-remote.moved file is updated with the latest Micro-Update afterwards. If it is not, apply this solution again.


dd0611b6086474193d9bf78e2b293040 56797cefb1efc9130f7c48a7d1db0f0c a914db3fdc7a53ddcfd1b2db8f5a1b9c 29d1e90fd304f01e6420fbe60f66f838

Email subscription for changes to this article
Save as PDF