Hi bill,
A simpler way would be to select all the messages in your inbox that you want to back-up. To select many messages at the same time, click each message while holding your Ctrl button. After, still keeping those messages selected, right click and select "Forward Items". When you click that a new message box will open up, you will notice that all the emails you selected will be attached in that message. Type in the gmail account you would like to send it to and thats it!
hope this helps!
Melissa