Run SENDMAIL as it’s own different user
You may need to change Sendmail to run as another user instead of root. In order to do this, run the commands below. We are using sendmail for the user, and sendmail for group. Make sure to stop the sendmail service by using the service sendmail stop command. You may also need to kill any running processes by using the killall sendmail command.
groupadd -g 24 sendmail
useradd -u 24 -g 24 -M -d /var/spool/mqueue \-s /dev/null sendmail
chown -R sendmail:sendmail /var/spool/mqueue
chmod 700 /var/spool/mqueue
chgrp -R sendmail /etc/mail
chmod -R g+r /etc/mail
chmod g+s /etc/mail
Now edit the /etc/mail/sendmail.mc file, and add the following directive to it:
Once these steps are performed, you can restart the sendmail service by using the service sendmail start command.