Article ID: 3059, created on Nov 12, 2007, last review on May 11, 2014

  • Applies to:
  • Operations Automation


Some ISPs (Internet Service Providers) can block outgoing SMTP connections on known ports (25, 587, 2525) and users require to open one extra port for the SMTP service.


On a POA-managed qmail hosting platform the SMTP service is invoked by the xinetd super-server each time when a user connects to the server.

To add one more available port (e.g. 1024), one can create the /etc/xinetd.d/smtp1024 file on a qmail server with the following content:

service smtp1024
    type = UNLISTED
    disable = no
    port = 1024
    socket_type = stream
    protocol = tcp
    wait = no
    user = qmaild
    group = qmail
    server = /usr/local/qmail/bin/tcp-env
    server_args = /usr/local/qmail/bin/qmail-smtpd /usr/local/qmail/bin/cmd5checkpw
    cps = 0 0

and restart the xinetd service:

# service xinetd restart

After that it is possible to test the port using the telnet utility:

$ telnet localhost 1024
Connected to localhost.
Escape character is '^]'.

The server responds with SMTP greetings, so it is configured to serve connections on the port 1024.

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SMTP port



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