Buying a hosting at Dynadot just for an email account isn't a good choice.
You can do two things:
1. You can use email forwarding.
You will be able to send an receive email from
[email protected]. Just set up email forwarding to for instance
[email protected]. This will enable you to receive email. Then inside your gmail go to:
Settings > Accounts and Import > Send mail from another address
2. You can use google apps (doesn't require a hosting account)
Check this:
http://www.dynadot.com/help/question.html?aid=215
Then start here:
https://www.google.com/a/cpanel/domain/new