John -
Highlight the e-mail in Thunderbird, click on 'view' at the top of the page, and then select, 'Message source', this will give you all the info as to the origin of the e-mail.

art -
In Thunderbird, highlight the message and click Ctrl-U

In the other program I don't have to open the email to see the source, I can't see anyway to highlight without opening the email.

Which I don't want to do.

sandra