How to display html template inside an email

Hi experts,

My requirements is to display html template inside an email. In IM update form we have send email link and when we clicked on the link it will open an email. Our requirement is, if assignment group is in any of the tier 4 value, checkbox is checked, and if we are clicking on the send email it should contain a template with the last update, press etc of that incident. I am using SM-9.40.

Could you please help me to implement this??

Thanks & Regards,

Sandhu Mol