Hundreds of "delivery has failed" messages

[karmagirl70]

Over the past few days I have received literally hundreds of Delivery Failure Notifications. I have run virus scan and no one in my address book has received any weird messages from me.  Here is the header information from one of the emails.  Anyone have a clue what is going on or how I can stop this?

This report relates to a message you sent with the following header fields:

  Message-id: <0M5Z009XE5HEVK70@vms173003.mailsrvcs.net>
  Date: Thu, 21 Jun 2012 19:52:10 -0400
  From: "Gjopqkgm Vsxhcf" <lynn.katz@verizon.net>
  To: boortl@hotmail.com
  Subject: jivuk

Your message cannot be delivered to the following recipients:

  Recipient address: sifon-int@execs.com
  Reason: Remote SMTP server has rejected address
  Diagnostic code: smtp;550 5.1.1 <sifon-int@execs.com>... User is unknown {mx-us005}
  Remote system: dns;mx0.gmx.com (TCP|206.46.173.3|16945|74.208.5.90|25) (mx0.gmx.com GMX Mailservices ESMTP {mx-us005})

Reporting-MTA: dns;vms173003.mailsrvcs.net (tcp-daemon)
Arrival-date: Thu, 21 Jun 2012 10:53:45 -0500 (CDT)

Original-recipient: rfc822;sifon-int@execs.com
Final-recipient: rfc822;sifon-int@execs.com
Action: failed
Status: 5.1.1 (Remote SMTP server has rejected address)
Remote-MTA: dns;mx0.gmx.com (TCP|206.46.173.3|16945|74.208.5.90|25)
 (mx0.gmx.com GMX Mailservices ESMTP {mx-us005})
Diagnostic-code: smtp;550 5.1.1 <sifon-int@execs.com>... User is unknown
 {mx-us005}

[Hubrisnxs]

They probably just have your password!   Reset your User ID & Password ASAP!

[thejohn]

Who is "they" ......

[armond_in_nj1]

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@thejohn wrote:

Who is "they" ......

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The folks who wrote these messages 15+ months ago.