Strange email message

[Michael Sullivan]

I've been getting a strange email message once or twice a day for the
past week.  I use evolution, and I keep getting this email message:  


Date: 25 Jun 2004
19:23:44 -0500
From: Mail System
Internal Data
<MAILER-DAEMON at bullet.espersunited.com>
Subject: DON'T DELETE
THIS MESSAGE -- FOLDER
INTERNAL DATA
Message-ID:
<1088209424 at bullet.espersunited.com>
X-IMAP:  1088209423
0000000001
Status:  RO
X-Evolution-Source:
mbox:/var/spool/mail/michael
Mime-Version:  1.0

This text is part of the internal format of your mail folder, and is not
a real message.  It is created automatically by the mail system
software.
If deleted, important folder data will be lost, and it will be
re-created
with the data reset to initial values.

I don't want it in my inbox and the message says not to delete it, so I
move it to another folder.  It gets sent again.  It's really annoying
me.  Can anybody tell me what this message is and how to stop it from
coming?

-Michael Sullivan-