See Header Tools Lite for an alternative Rated 3 out of 5 stars

See https://addons.mozilla.org/en-US/thunderbird/addon/header-tools-lite for an alternative that works with newer TB versions.

Love this add-on Rated 5 out of 5 stars

Please do keep it going .. even make it donationware if need be. I use this to organize ALL my email stuff and go nuts without it.

Thanks for taking the time to keep it updated...

Still working with a little twist Rated 4 out of 5 stars

This tool isn't supported any more but was updated somewhat to work with TB 3 (TB_Header_Tools_0.7.2-tb3.xpi); please follow this link: http://nic-nac-project.org/~kaosmos/test/TB_Header_Tools_0.7.2.xpi; author states that it's workin g with TB 7
I've continuously changed the release information contained
within the xpi-file container "install.rdf" which can be easily accessed using 7-zip.
Just change the line <em:maxVersion>3.*</em:maxVersion> to e.g. "<em:maxVersion>12.*</em:maxVersion> .
TB will recogise the add-in as valid to version 12!
No guarantee that this add-in will not interfere with other add-ins, but i've not found it yet to screw up my system.

For test/usage, please check out this http://nic-nac-project.org/~kaosmos/test/HeadersToolsLite-003.xpi

Lost without TB Header Tools... Rated 4 out of 5 stars

I'm really sorry this add-on is no longer updated. However, users interested in this functionality can look at Header Tools Lite:
http://nic-nac-project.org/~kaosmos/index-en.html

Rated 5 out of 5 stars

Information on how to get this working in TB 5 can be found here: http://www.dezertdezine.com/blog/thunderbird-changing-email-headers

Rated 5 out of 5 stars

Second only to QuickFolders this is the add-on that I have most use. And now I find that it is not available on TB5.
I don't understand why TB developers do not build in the possibility of of modifying the Subject line of received emails. It was a feature in Outlook long ago, but Outlook had some significant problems.
I get many emails that arrive with inadequate subjects, which I need to change to help me discover important emails more quickly.
At present I have to go through the "Edit message as new" just to change the Subject line. And I don't need to change anything else.
Anyway, this gets top marks for usefulness from me.

This user has a previous review of this add-on.

Same issue as ji (attached files problem) Rated 2 out of 5 stars

I'm using TB 3.1.10 and Header Tools 0.7.1 and attached files often get broken after I change the header. It seems to work fine with JPG files but most of my PDF and DOC files simply won't open because of this add-on.

attached files problem Rated 3 out of 5 stars

When i change the subject with tb header tools 0.6.6 (tb version 2.0.0.21)( just add ok), i can't open the attached files (*.xls) with ooo (3.1.1) no longer.

The add-ons mirror has a version that works with 3.* Rated 4 out of 5 stars

http://forum.addonsmirror.net/index.php?showtopic=1906 has a modified version of the add-on that supports 3.*, plus another 3.* version that includes a bug fix. Scroll down to the bottom of the web page to find them, the version at the top only supports 2.*See http://kb.mozillazine.org/Updating_add-ons for how to either bump the version number or bypass the version checking. If you do that it works with 3.1.6

Rated 5 out of 5 stars

An update working with all the releases 3.* can be found here. Une mise à jour fonctionnant avec toutes les versions 3.* peut être trouvée ici :


http://forum.addonsmirror.net/index.php?showtopic=1906&st=0&gopid=38064&#entry38064


It works very well with my 3.1.2 release of Thunderbird. Elle fonctionne très bien avec ma version 3.1.2 de Thunderbird.

Rated 5 out of 5 stars

This extension was the main reason why I switched to Thunderbird and now it is unavailable for 3.1 version :-(. I hope someone who is more into it will fix it and post it cause I know that Frank doesn't work on it for years.

Rated 5 out of 5 stars

really good and helpfuhl extension.
Unfortunately not jet compatible with TB 3.1

Highly recommended
Thanks
Torsten

Unstable Rated 4 out of 5 stars

I install this ver.0.7.1 into TB 3.1.
When I change View - header - all -> normal , the header will no longer be displayed.
And when I use this with the Display Mail User Agent extension, incorrect user agent may be displayed. I am waiting for improvement.

Rated 4 out of 5 stars

I am running WinXP and just installed TB v.3.0.5.
I downloaded and installed TB_Header_Tools_0.7.1-tb3.xpi .
from http://forum.addonsmirror.net/index.php?showtopic=1906&st=0&gopid=38064&#entry38064
(it was a link towards the bottom of the page) Note to download the 0.7.1 and not the 0.7.0
0.7.1 does not work on thunderbird2

It worked with no problems did not break anything and works on my IMAP without deleting attachments.

Right-clicking on a message does not bring up "Change Header Details". (It used to)
Instead, click on Message>Change Header Details.
Installation of the XPI file was normal for adding a saved extension.
Click on Tools>Add-ons>Extensions>Install

4 out of 5 because right click on email does not work
This is still my most important extension!

Special note - you can still drag email to desktop - edit with notepad and drag it back to Thunderbird. Making sure that you still have extensions turned on so you can see the ending .eml and dont save it as .txt (just find where it says "Subject" and make the changes after this word.

Header Tools Extension Rated 4 out of 5 stars

I am running WinXP and just installed TB v.3.0.4.
I downloaded and installed TB_Header_Tools_0.7.1-tb3.xpi .
It worked with no problems.

Right-clicking on a message does not bring up "Change Header Details".
Instead, click on Message>Change Header Details.
Installation of the XPI file was kind of tricky.
Click on Tools>Add-ons>Extensions>Install

Four Stars because the Right-click feature is not enabled.

Rated 3 out of 5 stars

Im having trouble installing any of the versions posted, I chose the option to open with thunderbird when im downloading it and nothing happens, any advice for a beginner?

Rated 5 out of 5 stars

I tried the latest unofficial fix (version 0.7.1 by Ray Stevens) from http://forum.addonsmirror.net/index.php?showtopic=1906
It works great on my TB 3.04 (both 32-bit and amd64) and does not break Junk Mail filtering/moving. Thanks a lot to all who contributed to it!

BTW, http://forum.addonsmirror.net/index.php?showtopic=1906&#entry24444 is a good intro how to use this extension, while http://forums.mozillazine.org/viewtopic.php?t=279907 is very outdated.

Breaks Junk Mail filtering. Rated 2 out of 5 stars

I was so happy to see this extension. My IMAP server puts in a a Spam score on messages that it thinks is spam. This is form of [***Spam*** Score/Req (number)/5.0]. Sometimes the server falsely ids a message as spam when in fact it is not. So I am stuck with the spam id. This works but it breaks another primary feature.... Spam filtering. If a message is marked as spam it Thunderbird is set to automatically move the message to the spam folder but with this extension installed it doesn't more the message.

Rated 5 out of 5 stars

You can download the updated version, working under Thunderbird 3
http://forum.addonsmirror.net/index.php?s=949280708228b64da1c7a7931301e700&app=core&module=attach&section=attach&attach_id=1606

Rated 5 out of 5 stars

Not sure if this extension is supported any longer, so thanks to Frank for what was a very helpful extension during its hay-day, and thanks to thekitehunter below for a new way to edit mail in TB3.
Blessings.