When I send mass mail out ,I click on send as tex  ,it is sending it out as html

<p>Dear Member,</p><p><br></p><p>We would like to wish you a very happy new year.</p><p><br></p><p>ukadoptionregister is now back online ,we or sorry for the inconvenience.</p><p><br></p><p>Regards</p><p>Admin</p><p><br></p><p>{http://ukadoptionregister.org}</p>