ANSWER: Really, for the purposes of our site, the personal message you complete when you apply is the equivalent of the cover letter. Since you’re not mailing it and it’s processed through our system, you don’t have to spend time worrying about formatting an address at the top. Just start with the main body.
If you’ve already typed up your cover letter in a document or through our cover letter tool, simply open it up in a display mode and copy and paste the text. Be sure to include a salutation and a closing salutation.