It runs as a regular Unix user with ordinary privileges. Hence Harry Hacker's instructions won't be running with superuser privileges. Another big reason that Post. If they aren't ever going to drive a Unix shell, then they should just be added as a Post. Office user for POP delivery or forwarding.
Office is way faster and consumes fewer system resources than sendmail.
However, like sendmail and first-generation Web server programs, Post. Office forks a process for every message sent. Office doesn't really provide an easy way to do this. Office provides program delivery. It will pipe mail to the Unix program of your choice.