To copy header information as text, use the 'view source' route and copy the appropriate lines to paste into another text area.

Or you can save the header as an image using one of the many screen capture applications that are widely available. Windows has the 'Snipping Tool' built in. You can use OCR to extract editable text from the image, but for single messages, the 'View Source' is faster and easier to implement.

TB-38.3 Win10-PC

In MS Outlook, I click Forward, and then copy the header from the compose window where it appears above the message I'm forwarding. It's fast and then I just discard the draft message.

Does that work in Thunderbird?

(That has From, Received (Date/Time), To, and Subject, but not Reply-to, at least in the case of an Outlook forward.)

Well, I see that there is usually a block near the end of the header such as:

From: "Seagate Technology" <mail@messages.seagate.com> To: ral@raleeper.com Reply-To: "Seagate Technology" <mail@messages.seagate.com> Date: 13 Oct 2015 22:43:00 -0400 Subject: =?utf-8?B?U3Bvb2t5IFNlYWdhdGUgc3RvcmFnZSBzYWxlISDwn5G7?=

and sometimes the subject is valid and readable, but there ought to be an easy way to extract just the part of the header that is shown but that cannot be copied when view headers is set to "normal".

to jscher2000 Yes, that seems to work in TBird.

Thanks, Robert

@jscher2000,
I tried your method - forward the message, but do not send - copy the header data from the compose window - paste into Notepad or elsewhere. Individual lines can be copied and pasted where needed.

TB-38.3 Win10-PC