PHP :: mail() function

[dionyzos]

When I send a message to someone using the php mail() function, it looks like HostRocket adds the following:

Message-Id: <E16VH7z-0005Ld-00@host21.hrwebservices.net>
Date: Mon, 28 Jan 2002 14:07:39 -0500

Any Idea how to strip that? There is something I must be doing wrong and it doesn't look great for my customers.

Thanks in advance.