Here is a reply from O.P. Tech Support

From: Micah (O.P. Tech Support)
Subject: Player seems to be continually posting to the forums

The problem is that his/her email program is not properly identifying the
emails as auto-replies. Our system is set up to recognize properly
identified auto-replies and ignore them when generating new forum posts.
Plus, the emails we send properly identify themselves as auto-generated, so
auto responders should recognize that and not respond. Unfortunately, a lot
of email clients don’t do things right.

There are a couple things to do to “fix” it

1) Delete the forum thread, this will stop the reply infinite loop
2) Have that player edit their settings and un-select forum replies.
or
2) Have that player turn off their auto-responder

We’ll have to eventually figure out a better way to handle things, but it’s
frustrating since the bug is really not with our system