I have Netscape 4.61 as a Backup and don't use it for email. I did look around and here's what to do. It may vary according to your version.
Open Messenger and go to the toolbar to Edit>preferences
Click on "Mail Servers"
Highlight the service you want to use as the default and press the default button.
Also, I have to tell you that many people do not have Works installed. Doing your resume in Works may not be the wisest choice because it won't be viewed by businesses. If it is too hard to open and view, they may not even read it.
Everyone has Word Pad. I would seriously consider redoing it and saving as a Word Pad Document.