The builtin html editor used to edit emails and email templates is very restrictive and troublesome when using copy/paste.
- Font end up different for pasted text
- Formatting options are minimal (eg. no tables, etc)
The current workaround that most people use is to copy the email text from the template into notepad/word, edit it there and paste it back. The Problem then is that formatting is lost altogether along with hyperlinks (if done in Notepad to avoid font issues).
Please consider including an already accepted standard editor like Telerik's RadEditor or CKEditor to provide users with a more workable emailing method.