Sendmail takes an abnormally long time to start, or is found to stopped at regular intervals.

Issue

• When sendmail is started or restarted on a RHEL server, it takes a couple of minutes before sendmail will start completely.
• Sendmail was also found to be in the stopped state at regular intervals.
• The below are seen in the /var/log/maillog:

Sep 11 04:52:14 hostA sendmail[11601]: My unqualified host name (hostA) unknown; sleeping for retry
Sep 11  04:53:25 hostA sendmail[1601]: unable to qualify my own domain name (hostA) -- using short name