Notification emails not sending correctly

When I log a new call and the notification email is sent, it doesn't send correctly:-

if I specify emails to go as HTML they don't, they go as plain text
If I specifiy as plain text, they go as plain text but with errors (see below this is as it appears in BOTH HTML and PLAIN TEXT emails), this all worked fine when we tested the product (same version) a few weeks ago.

Mime-Version: 1.0
Content-Type: multipart/related;
boundary="----=_Part_4_28630635.1156162480636"

------=_Part_4_28630635.1156162480636
Content-Type: text/plain;charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

Dear MR TEST

Thank you for your recent Servicedesk request; your request has been create= d with id 5. The title of the request is : yet another test. The status of = the request can be tracked at http://fch-helpdesk:8080/WorkOrder.do?woMode=
=3DviewWO&woID=3D5 .

regards,
ICT=C2=A0Servicedesk

------=_Part_4_28630635.1156162480636--