Review for TB Header Tools Extension by Ray Stevens
Rated 4 out of 5 stars
As mentioned below, I have a simple hack that enables this for TB 3.0.
To get a copy of rev 0.7.1 with the hack, go to:
http://forum.addonsmirror.net/index.php?showtopic=1906&st=0&gopid=38064&#entry38064
I rate this 4 stars -- I'd love to see this built into Thunderbird itself.
Usage note: look for "Change Header Details" in the Message pulldown menu from the main toolbar.
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