Strange error: ^A^@^@^@^N

Hi all,

When a user tried to correspond to a ticket, the email got bounced
by our email server with the following message:

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

local delivery failed

The following text was generated during the delivery attempt:

------ helpdesk@ ------

RT server error.

The RT server which handled your email did not behave as expected. It


It happens very rarely, though.

Also, when I try to refresh my browser, it sometimes asks me if I wish to
download a binary file. I downloaded the file and saw that it contained
the same five characters as above (^A^@^@^@^N). I do not know
if they are related or not.

Any help would be greatly appreciated,