strange html tracking messages received when sending email

im getting the following notifications to notify me of message tracks:

=?UTF-8?Q?_home?=
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="----=_Part_12867_728468635.1399033164610"
X-mxHero-ShortCodeRemoverFilter-Ignore: true

------=_Part_12867_728468635.1399033164610
Content-Type: multipart/alternative;
boundary="----=_Part_12868_568076898.1399033164610"

------=_Part_12868_568076898.1399033164610
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Email Tracker

Email sent to xxx@gmail.com has been opened.

#ifnotnull( )
Details: {0}


Click Track powered by mxHero Inc. - http://www.mxhero.com">mxHero
Copyright 2011-2013 mxHero, Inc. All rights reserved
------=_Part_12868_568076898.1399033164610
Content-Type: text/html; charset=us-ascii
Content-Transfer-Encoding: 7bit

[snip]

then the rest of the original email in html