Email notifications not working

Our email notifications are sending "rubbish". They are set to HTML, but send as per below:-

Some are working, but most aren't, this one being the MOST annoying.

Mime-Version: 1.0
Content-Type: multipart/related;
boundary="----=_Part_5_17464620.1156166907714"

------=_Part_5_17464620.1156166907714
Content-Type: text/plain;charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

Dear USER,

Thank you for your recent Servicedesk request; your request has been create= d with id 6. The title of the request is : test with workstation. The statu= s of the request can be tracked at http://fch-helpdesk:8080/WorkOrder.do?wo=
Mode=3DviewWO&woID=3D6 .

regards,
ICT=C2=A0Servicedesk