I just noticed when launching my terminal a message "You have new mail." I would like to know if someone is trying something malicious with my email and name.

The mails are all returns from the same server. There are 20 of them:

N  1 MAILER-DAEMON@ussjoa  Tue Nov 10 16:57  73/2522  "Undelivered Mail Retu"

Each message appears to be the same, some sort of attempted registration (note: I omitted my personal email address from the following code):

--6A9539564F2.1257902972/ussjoaboynton3.us.deloitte.com
Content-Description: Undelivered Message
Content-Type: message/rfc822

Received: by ussjoaboynton3.us.deloitte.com (Postfix, from userid 501)
        id 6A9539564F2; Tue, 10 Nov 2009 17:29:32 -0800 (PST)
To: [email protected]
Subject: Your registration informaton
From: **(personal email address omitted)**
Message-Id: <[email protected]>
Date: Tue, 10 Nov 2009 17:29:32 -0800 (PST)

First Name: as
  Last Name: as
        Email Address: as

        Username: as
        Password: F!ekUXN3

--6A9539564F2.1257902972/ussjoaboynton3.us.deloitte.com--

byte 2302Diagnostic-Code: X-Postfix; unknown user: "as"

Any information to help figure out what is happening is greatly appreciated. Thank you.