Can I set my email to be spell checked with word perfect or another program?

It really depends on the mail program you’re using more than anything else.
Microsoft Outlook, for example, will not only spell check using Microsoft Word
but will allow you to edit your mail with Word as well.

I’d look at the documentation available for whatever mail program you’re
using to see if you can have it interface with another spell checker or word
processor. Unfortunately I believe that chances are slim.

What I often do as much for formatting as for spell check is to compose
mail my in on program – a text editor – and then when I’m done with it
copy/paste it into my mail program. It’s not perfect, but it works.