it is not possible to modify email subject

I think this should be marked WONTFIX, as changing the subjects isn't really
something a mailer should do.
Using the labels on the other hand...

*** Bug 165409 has been marked as a duplicate of this bug. ***

*** Bug 142887 has been marked as a duplicate of this bug. ***

Hi Morten,

I do this every day and its a really good feature. The risk of changing a
document can't be taken in account, because there are many ways to do so, just
not in a comfortable way

In fact, I'm already waiting for the feature ;-)

I strongly vote for this feature, as I stumble nearly everyday
about the problem of finding a mail about a subject wich has
not been described sufficiently (the typical 'Hi, how are you'...).
I think it can not be too difficult to make that field editable.
There's also no link to any security question etc pp., its
just the problem of finding someone to be able and willing to
implement it.
I'm willing, but not able. Any volunteers ?

BTW, this would not be that urgent if it would be possible
to search for words in the mail BODY, which is not
implemented yet. But until that is done, this easy feature
is the only way to find mails about a certain topic.

This is more about getting people to have meaningful headers in their emails,
and shouldn't be something that a mailer should do. You can set up a folder
for Important Mail and drag an email there, and adjust your flags so you can
tell what kind of mail this is, so my vote is for a WONTFIX

Graham, unless you finish fixing the world, we have to stand some, say 'less
clever' guys wanking around. We have to stand non-geeks around. We have to stand
managers. And some of them are maybe your business partners. And they give you
or your company buck or two. So you nether can kill them, nor send them some
"F"-words back when there come the day you get hit by HTML mail with all these
lovely backgrounds, anim-gifs and colors we all adore. Or imagine they send you
important mail w/o proper subject (being in hurry ain't that unique). And you
want to keep it anyway, 'cos it's THE mail. Prefer having tons of same looking
mails with funny flag in special folder, or you would consider 'fixing' the
subject? To get the point: you don't need it - you won't it. But also don't
speak in the case if this not apply to you please, or consider there may be
others than you using Mozilla too...

Because it seems to me a relatively simple task to add it,
and there are surely a lot of people who also would find
this very helpful, I would oppose a 'Wontfix'. If I had
time I would implement it myself.

I just voted for this feature.

I agree, it would be a better world if people wrote descriptive subjective
headers all of the time.

I'm not expecting it to happen anytime soon though :)

I voted for this feature request becuase I would find it very useful and I think
many other mozilla users would find it useful.

By implementing it many people will be made happy, they will get use out of it,
and it will be one more factor in making mozilla popular.

What better return for your coding efforts can you ask for? :).

Steve

just to confirm the upper lines ...

You know it,
the secretary does it, the manager does it, the softworker does it and even the
book-writer does it, and so on:

if people don't give a good subject, he or she will change it!
You think about, how they do it? It's easy - they are using Outlook.

Ok friends, is this the reality You are looking for?

We don't talk about a feature, that no one should have, at least half of all
user use it already and it makes sense in addition.

If I want to fake an email, I just need to open the mail-folder-file. Any more
questions?

Please integrate the feature!

User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3b) Gecko/20030206
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3b) Gecko/20030206

Current options are moving to folder, labeling the message, etc. but it would be
nice to be able to modify the subject line of matching messages to visually
separate them. ie. message from <email address hidden> comes in with a subject of "hey"
and the subject line is rewritten to be "[FOO] hey"

Reproducible: Always

Steps to Reproduce:
1.
2.
3.

I don't think that changing any part of a message is a good thing[tm] (so I'm on
the side of WONTFIX).

But then I guess a searchable/displayable "recipient's comments" feature
could be valuable.
The comments could be stored in the .msf and would be available both as
a search option and as thread pane column.

(Would this be worth a separate bug?)

Maybe an alternative, but I think it's much more complicated to implement
than the original proposal. I also think that changing the body of a mail is
not a good idea, but changing the subject line is not harmful in my opinion.
But if we find someone to implement the complicated case, it's ok from my view.

Changing received mail is considered data loss.
See also discussion in bug 91106.

Storage in in the .msf file is perhaps not a good alternative since I have to
delete my .msf files from time to time and would loose the valuable new subject
lines.

Often I am copying my mail archives from one PC (e.g. my Windows laptop) to
another PC (my Linux workstation), after "compressing" the mail files. I
consider the .msf files not as part of the archive content but just as temporary
index files.

In addition, the msf files are automatically rebuilt each time my mozilla
browser crashes due to some java or shockwave content while a mail window
happened to be open at the same time...

> consider the .msf files not as part of the archive content
> but just as temporary index files.
>
> In addition, the msf files are automatically rebuilt each time my mozilla
> browser crashes

Good points, but IMO:
- mails should not be altered
- comments are not part of the mail and do not belong into the mbox

So we'd need to put the comments into the msf (with the above problems) or we'd
need another file for the comments (which isn't desirable for performance reasons).

Since the msf problems are actually "just" bugs, I'm still in favor of that
solution - it would delay this bug until after resolving them, though.

This discussion makes me really nervous now. The purists among the community
want to tell us, that it is not a good thing, to change a subject, because it
changes some kind of document. Ok, if You don't want to do so, its ok. But why
You want to force all the others to be like You? I can tell You, what I do, if
the feature gets WONTFIX: I will uninstall this mailer, and get me another one.
You cannot force us to act in Your way.

In comment #14 Martin Rosenbauer said :
> Storage in in the .msf file is perhaps not a good alternative since I have to
> delete my .msf files from time to time and would loose the valuable new subject
> lines.

Yes, the additionnal comments belong to the MSF file, just as the message flag
and the message label.

In comment #16 Peter Möller said :
> Ok, if You don't want to do so, its ok. But why You want to force all the others
> to be like You?

well, I'm thankful there are people that sometimes decide to label a bug
WONTFIX. Not doing so will inexorably lead to total mess in Mozilla developpment.

But Mozilla Mail is not the only mailer, you can post your request on the
Thunderbird forums on [http://www.mozillazine.org/forums/] , they may have a
different opinion.

As I wrote in npm.m-n:
If we want to store internal data in X-headers, we have to make sure that
- all headers must get out of storage *exactly* as they have been put there
- internal headers must not 'leak' to the outside
That way, we could store comments etc. in some X-Mozilla-Comments header that is
only visible to Mozilla itself and would, eg., not be saved when saving messages
to files. (The mbox format already 'escapes' certain lines to work around problems.)

Alas, Mozilla's mbox handling is not 'transparent' in that respect (yet?), see
the empty line problem in bug 141983, bug 67391 and others.

I have seen numerous mailers handle this as such: when you change the subject,
your new subject appears in the message list, but when you view the message the
original "subject:" header remains unaltered.

*** Bug 220786 has been marked as a duplicate of this bug. ***

This is argument is very peculiar

  1) Let users edit subjects if THEY wish.

  2) If a user values emails as documents set in stone, then that user is not
required to use this feature.

  3) I desparately need this feature. It is one of the two major reasons I will
not want to use Mozilla soon....

  THOSE WITH THE ABILITY TO FIX THIS: Please implement this soon!??!? (Many thanks!)

*** Bug 229222 has been marked as a duplicate of this bug. ***

C'm on Guys!

Is this really a chat thread for developers or just time capitalists that don't
know what else to do with their time? How hard can it be to realize the benefits
to the users this feature would bring?

The only blocker for this enhancement that I can see here is prestige. There has
not been presented one single rational argument to not implement this during one
year of ongoing discussion. There is no technical one - at least none I'm aware
of. Please prove me being wrong here.

Once a user has recieved a message, it's up to the user to decide what (s)he
wants to do with the message. Delete it, edit it or whatever. (S)he must take
take the consequenses of it anyway. If the sender wants to safeguard that the
"intellectual" contents of the message is not altered without being able to
prove that, then (s)he should choose to sign the message (or encrypt it), either
using S/MIME, PGP/MIME, or plain PGP.

None of the techniques above will become broken by changing the Subject Text of
the message. I've just verified that for all the six possibilities. Works like a
charm in Mozilla 1.5.

Another, at least as I see it, rational reason to allow changing the subject,
that has not been mentioned on this tread before, is the one that I reported
yesterday as Bug 229222 (and redirected to this thread).

For your convinience I include it here too:

Some of my mail forwarding services have started to "play" with spam
notification filters which, e.g. prepend "*** SPAM ***" to the subject line.
Unfortunately this once in a while gets added to the subject line of mails that
I receive from mailing lists. This, of course, breaks the sorting of mails by
"thread", and I thus have to manually open the Mail Folder with my Editor,
search for that particular mail and edit the subject back to it's original. I
don't see any reason to not allow this to be done via the Subject line of the
Header Pane in the Mail Viewer. And to my knowledge this shouldn't affect
signed/encrypted mail either.

This would also be useful when for changing an "internationalized" Reply Prefix
e.g. the Swedish "SV:" to the more common "Re:" which gets posted now an then to
 mailing lists where mainly english is spoken/written.

./.

This was annoying in Netscape, in Mozilla even more. Why?
Well, in Netscape one could switch to another folder during the edit, but in
Mozilla that isn't enough. One has to exit Mozilla and reenter, otherwise
something gets messed up and every mail is shown twice in the Mail Pane of the
Main Mail Window after the edit. Not to mention that, one will loose all labels
assigned to mails before the manual edit.

Concerning where to store the edited Subject Text; the answer is simple - in the
header of the mail. How should I otherwise, i.e. if that text has been stored in
the .msf file, be able to see that change when accessing my mail via my web-mail
client instead of via Mozilla (IMAP)? If you, for some reason, want to store the
original Subject Text somewhere, that's all right with me. Even in that .msf
file. I certainly do not care. But I'd suggest to add a new property header like
"X-[Mozilla-]Original-Subject: ..." to the message header (if there doesn't
ex...

*** Bug 236811 has been marked as a duplicate of this bug. ***

(In reply to comment #25)
> *** Bug 236811 has been marked as a duplicate of this bug. ***

But 236811 was filled for Thunderbird, while 91106 was filled for Mozilla suite
(And Mozilla suite guys do not seem to want to implement it for some strange
puristic reasons).

In addition to being able to edit the subject line for the incoming mail
summary (not in the msg header), some users need to be able to insert a short
note into the body of the msg for future reference. For example, I receive
many technical newsletters and E-mails, and often insert short notes (like a
footnote) referring to some URL or other E-mail for related information.
The lack of this feature in Mozilla Thunderbird is a major reason preventing
me from switching. Eudora has this toggle - the Pencil button toggle, which
makes it possible to save it to the original msg.
Thunderbird has an "Edit this message as new" feature, but it saves the
modified msg separately in a different format, but it's clunky & doubles the
storage space required..

Such added noted, if not going into another file, have to go into the header
part of an message or the signature verification of signed messages will become
broken.

Thus adding messages *into* the body of a message is IMHO not an option.

1. I would be against including the information into the .msf file - i keep my
messages on an IMAP server and access them from 3 different computers (work,
home, notebook).

2. Why not include a separate field into the header set this field to the same
value as subject by default and then allow changing it. Various programs (spam
filters) include their fields into the header so the purists do not have to be
woried. You could switch this feature on or off.

Maybe itt would be also useful to allow including one more field for longer
comments (but this would not be included automatically).

(In reply to comment #29)

With all respect, the feature you suggest (as point 2.) might be useful to some
people, even though I don't know precicely for what. But, if implemented, I
think it should be optionally configurable; not done by default.

My primary, and *urgent*, need for this feature is to actually restore subjects
to their original value again after having become "trashed" (e.g. by prepending
"*** SPAM ***" to the real subject), e.g. by external MTA spam filters (that are
not under my control, like http://www.snert.com/Software/milter-spamc/, etc), so
that those messages *again* will be filtered into the message thread they are
supposed to. For this purpose there is no value added by storing the "original"
subject.

Performing this task, by editing the mail file for each and every mail with an
"trashed" subject, is becoming more and more frustrating for every day and thus;
I'd like this primary and, IMHO for most of us, very useful feature to be given
a high priority.

(In reply to comment #30)
> (In reply to comment #29)
>
> With all respect, the feature you suggest (as point 2.) might be useful to some
> people, even though I don't know precicely for what. But, if implemented, I
> think it should be optionally configurable; not done by default.

I would also prefer direct editing of the subject, but it looks as there is no
way to get that since it is opposed for some puristic reasons. With the option I
suggested I would simply forget there was ever any Subject field and display the
new field as if it were subject field.

My reasons for this feature:
(1) the one you said with SPAM tagging,
(2) assigning reasonable subjects to articles I sent from various websites (e.g.
changing "An article from financialnews.cz" to "Mortgages from financialnews.cz"
(3) changing recycled subject: "re: problem with PDA" -> "How to get to the airport"

(In reply to my own comment #30)

> With all respect, the feature you suggest (as point 2.) might be useful to
some people, even though I don't know precicely for what.

Actually, now, I *can* see at least one feature for which saving the original
subject in a separate header field could be of use. But that feature should be
implemented as an extension, that may *optionally* be enabled/applied *after*
direct editing the subject (e.g. for one of the reasons mentioned in comment
#31). If, after enabling this feature for an message, any follow-up messages
received with that same original subject *automagically* would be substituted by
the new subject, then that would be really useful.

But, the above suggested feature *should not* be considered if it in any way
delays the implementation of direct editing the subject line; e.g. as described
in comment #31.

I do willingly admit that I haven't analysed and considered any side-effects
that this might have. It was just an idea that happened to cross my mind.

 Can we have some common sense please?

 Enough people have asked for a feature. It is a simple feature compared to
other sections of the project.

 Just because some people have a philosophical objection does not mean that the
remaining users should lose the feature. Surely like many other features it can
just be an option able to be turned on through preferences or even just through
"about:config".

  BUT PLEASE can we have the feature?????

  I like many other people are looking for a better client because of this major
annoyance.

Just 'vote'-ed. An useful feature .. waiting for a long time.

Is there any activity concerning this feature? I'm kind of worried since the
last thing that happened here was over 3 months ago...

M$ Outlook has this feature... while it's not enough to stay with outlook, it
has been missed.

There is an extesion available for this!

The link (and discussion) is at:
http://forums.mozillazine.org/viewtopic.php?t=89134

Does the extension mentioned in comment #37 work with Mozilla too, or is it a
Thunderbird only extension?

*** Bug 539227 has been marked as a duplicate of this bug. ***

I voted strongly in favor of implementing this function...but it does not seem to be going anywhere, since it is over 5 years old, and still on the back burner. So, I am not holding my breath on WHEN it might get implemented.

I have been using Eudora since version 1 as a paid subscriber. And, I still use Eudora v7 on my main system simply because the open source version does not support the "change SUBJECT LINE" function. I do use Eudora v8 on my laptop (while traveling) and find it quite nice, EXCEPT for the missing function.

*** Bug 564181 has been marked as a duplicate of this bug. ***

A generalization would be editing of arbitrary mail. It would be very similar to "Edit as new", but instead of the "Send" button, you would have a "Save and close" button, and then the message would be replaced.

@Jens: RFE for editing mail body is bug #254739. That bug has over 100 comments already and does not seem to get implemented soon.

So I hope that this RFE here gets implemented.

I see no data-loss when editing subject as X-Mozilla header can be used to store modified/original subject.

See also Mozilla at getsatisfaction.com:

http://getsatisfaction.com/mozilla_messaging/topics/can_i_use_thunderbird_to_rename_a_subject_line_in_a_received_email

Apple Mail and MailTags can do this.

MailTags provides keyword tagging and adding of notes to mails. Notes can be set as subject. Full text search / Spotlight will find text in notes, too.

See http://www.indev.ca/MailTags.html

MailTags implements overwriting of subject by adding proprietary headers to mails.

Example:

> X-Mailtags: {
> "mailTagsAnnotation" : "Project Brainstorm: Req Meeting 2010",
> "mailTagsShowNoteAsSubject" : 1}

*** Bug 532153 has been marked as a duplicate of this bug. ***

If this get's implemented, Gloda (global indexer) has to be informed about the new subject entered by user. However, Gloda should not forget the original subject.

I also have been using TB Header Tools and now on extension 7.1 which has a basic problem in that when a msg is being viewed and I go to View/Change Header Details, then the msg in focus is changed. This can make it very difficult to write the appropriate subject since it's usually something included in the msg.

A good example of a daily change that is made is a msg from Cybernet where the subject always is "CyberNet Technology News." If such a msg is to saved the actual content subject needs to be entered. This is needed for a later quick search to find the subject. Of course, the subject frequently needs to be changed in received business msgs as well because writers frequently do not include a subject at all or the subject is not related to the content.

As far as the various fields and minimal instructions with the extension, I don't understand one iota so simply change the subject line and happy I can do that. It would certainly be appreciated if this extension were to be incorporated into TB as a feature that could be used by those who need it.

The TB Header Tools were not updated for a long time - the latest release on addons.mozilla.org is for TB 0.5-1.0 and the 7.1 "update" for TB 3.0 is just an unofficial hack. So it seems TB Header Tools will never be updated to TB 5.
I sometimes get messages without subject (from people in a hurry) and I want to be able to see what they are about when browsing the mailbox.
I

I am also looking for this for TB 5, and would like the same functionality TB Header Tools had, and the stability of that original add-on so my mail doesn't get hosed up as can happen with the "unofficial hack", as it was called above.

FWIW, I agree that the original subject should NOT be overwritten, as apparently happens with the MailTags suggestion listed above. The optimum implementation IMHO would be the ability to highlight the subject and just edit it right there (which even the nefarious Outlook has). Second most optimum is the right-click option method, and last (mildly inconvenient but worlds better than no option at all) is to drill down for the option through the Message menu.

It would be most ideal to have this functionality in TB itself...and even I'm okay with having to go into Config Editor to manually enable it.

Point of information: MailTags does NOT overwrite the original subject. The original subject displays when you view the message. The subject is only changed in the mailbox listing.

I agree that the optimum implementation, which the original Eudora does (I'm still running Eudora on my Mac and will do so until Lion) is the ability to highlight the subject and change it. Eudora has an editable subject line field at the top of the email message, as well as a Subject: display within the email that retains the original subject.

Why is this so difficult?

(In reply to comment #78)
> FWIW, I agree that the original subject should NOT be overwritten, as
> apparently happens with the MailTags suggestion listed above.

Sorry, my comment #73 may be misleading. MailTags does not overwrite the subject in the mail header.

Instead it adds custom headers to allow you to set your own subject line. This subject line will be displayed in message list pane (instead of the original subject line) and regarded in searches. However, you can always revert to the original subject line.

*** Bug 689055 has been marked as a duplicate of this bug. ***

I just found the new extension (as of Sept. 2011) "editemailsubject" (must be typed as written, without blanks, in Thunderbird's extensions search). It allows to edit the subject displayed in the mailbox window while preserving the subject in the message header. Exactly what I was looking for.

This addon "editemailsubject" doesn't upload the changed subject to the IMAP-Server.
Changes are LOCAL only.

The editemailsubject extension is POP-only, no help for IMAP users.

howdy y'all,

this extension from paolo kaosmos does the job. it replaces the old headertools extension mentioned in comment 37 and is actively supported.

- Headers ToolsLight: edit Subject, Sender, Full source etc
http://forums.mozillazine.org/viewtopic.php?f=28&t=2300561

it seems like a good workaround until tbird finally includes the ability.

take care,
lee

(In reply to Lee_Dailey from comment #85)
> this extension from paolo kaosmos does the job. it replaces the old
> headertools extension mentioned in comment 37 and is actively supported.
> - Headers ToolsLight: edit Subject, Sender, Full source etc
> [Forum] http://forums.mozillazine.org/viewtopic.php?f=28&t=2300561
> it seems like a good workaround until tbird finally includes the ability.

The addon can be downloaded from here (reported to work with TB24, and actively maintained):

https://addons.mozilla.org/de/thunderbird/addon/header-tools-lite/

*** Bug 947267 has been marked as a duplicate of this bug. ***

Why this is important:

1. You personally may not, but many users have fax->email services. For them, this feature is absolutely necessary. For a long time, I didn't realize that there was an extension that allows it and works well, the lack of which causing me a lot of pain.

2. If people set bad subjects for important emails (e.g. by just hitting reply on an unrelated subject), I can either get angry at them (because I will not find it anymore in one week), or ask them to fix it in the future, or I can fix it myself in my mail store. The latter, however, I can only do with this feature.

3. Many other people have wrong clocks on their computers, and Thunderbird sorts folders by the message send time that the sender put in. I recently received a mail which was exactly one month off. Completely confused me in the folder view. I can't fix it, without this feature. (Arguably, Thunderbird should sort better.)

This is similar to "delete attachment" feature. That's also a feature that we didn't have for a long time, and some said we didn't want it, they said it's freaky and wrong. Finally, we added it - and it's indispensable, as it turned out.

(In reply to Ben Bucksch (:BenB) from comment #88)

+1, I'd like to register my support for Ben's support of this bug :)

65 votes and 15 duplicates with consistent inflow over a large time span are a good indication that "edit subject" feature has the potential of adding significant value for many affected users.

Somebody care to search https://getsatisfaction.com/mozilla_messaging/ for user requests about this?

> Why this is important:
>
> 1. You personally may not, but many users have fax->email services.

If you are suggesting that a larger or in any way significant percentage of TB users use FAX-to-Email services, then imho that's a fiction from the same ideosyncratic historic world where plaintext messages are still so much the order of the day that we could just ignore the substantial dataloss of formatting/styles inflicted on users of HTML messages by your delivery-format "Auto-Detect" algorithm.

Having said that, I don't think small numbers of users for a given feature is per se an argument against that feature; if we removed all features each only used by small percentage of users, we would end up removing large parts of TB feature set. On the contrary, I'd claim that qualitative aspects like the degree of disturbance by lost ux-efficiency should also matter. Which might apply to this bug: It's hard to tell how many users would actually bother to edit subjects, but for those affected by such problems, it's a significant interruption to their workflows.

> For them, this feature is absolutely necessary.

+1

> 2. If people set bad subjects for important emails (e.g. by just hitting
> reply on an unrelated subject), I can either get angry at them (because I
> will not find it anymore in one week), or ask them to fix it in the future,
> or I can fix it myself in my mail store. The latter, however, I can only do
> with this feature.

+1

> 3. Many other people have wrong clocks on their computers, and Thunderbird
> sorts folders by the message send time that the sender put in. I recently
> received a mail which was exactly one month off. Completely confused me in
> the folder view. I can't fix it, without this feature. (Arguably,
> Thunderbird should sort better.)

This bug is only about editing subject; editing any other header fields (like date) is not in the scope of this bug, and should not. It'll be more than hard enough to just land "edit subject" in a generally acceptable and functional manner (think IMAP), so expanding the scope of this bug would be the perfect recipe for never landing anything.

> This is similar to "delete attachment" feature. That's also a feature that
> we didn't have for a long time, and some said we didn't want it, they said
> it's freaky and wrong. Finally, we added it -

+1, there seems to be some analogy of technicalities and historical development.

> and it's indispensable, as it turned out.

OT: I have some doubts on that, given that the "delete/detach attachment" feature still has bugs (like wrong icon for detached files) without much activity from users iirc.

My .02 clad coins worth:

I might use this feature, but honestly, all I do now is simply forward the email as an attachment to myself, with the new subject.

Since I don't do this very often, it isn't that big of a deal, but I understand the argument for someone who may have a different workflow from me.

That said, I would only support implementing this feature if the act of modifying the email was recorded.

Ie, it adds a new header to the email, something like:

X-SubjectModified: OLD: Blahblah; NEW: blahBlahBlahBlah

In other words, the evidence (old subject) is still there.

+1 for me. Still would benefit my use of Thunderbird for mail storage/archival. My partner at work often sends empty subjects. It's annoying as hell --- but what's even more annoying is having to keep telling him. I'd prefer to just add a modified subject to the email with a record in the email header as described by Charles. - Thx

Previous headers should be recorded as "X-Original-<headername>", e.g.:
  X-Original-Subject: Re: How are you?
  Subject: Appointment to discuss Bla project
If X-Original-Foo already exists, it is *not* overwritten.

*** Bug 685493 has been marked as a duplicate of this bug. ***

I fully agree with ben.bucksch' comment: it is good practice to keep a trace of trace of what the original Subject line showed.
Sometimes I like to edit the email itself to add comments/annotations to make the content more (re-)usable for myself. In that case I explicitly indicate (eg. by 'keyword' like "_ANNOTATIONS") that this was an entry added after receiving the email.
This feature is not 'comfortably' provided by all my favorite mail-clients though ;-)

It has been over six years since the last real discussion took place and almost two decades since the issue was created. Are there any objections from the Thunderbird team or hasn't there just been any volunteer to implement the feature?

I have another use-case for this feature: Many scanners nowadays can send emails with the scan attached. By default, though, these mails have a very generic subject. Being able to change the subject from the mail client conveniently allows finding particular scans later on.

I have been doing this in the past using the [Header Tools Lite](https://addons.thunderbird.net/de/thunderbird/addon/header-tools-lite/) addon. This addon, however, is not compatible with newer versions of Thunderbird. After looking through [Thunderbird's WebExtension APIs](https://thunderbird-webextensions.readthedocs.io/en/68/), it seems like editing an email's headers is no longer possible at all. It would be great if we could get at least an API to modify (or create new) mails.

I second the motion to add an API to Thunderbird that would allow changing the email subject in the folder list - not in the email itself, just like the last addon.

(In reply to Johannes Reiff from comment #95)
> hasn't there just been any volunteer to implement the feature?

Yes

> I have another use-case for this feature: Many scanners nowadays can send emails with the scan attached. By default, though, these mails have a very generic subject. Being able to change the subject from the mail client ... allows finding particular scans later on.
>
> I have been doing this in the past using the Header Tools Lite addon. This addon, however, is not compatible with newer versions of Thunderbird.

100% exactly my problem as well. This makes scan to email very hard to use. Everything has the same subject. Get 5 at the same time, and it's impossible to manage. Scan to email is a widely advertized feature of printers, so it's not a mainstream feature, and not marginal.