Thunderbird Reply All Is Sometimes Broken, Sometimes Missing

Question

I'm using Thunderbird 60.3.0 and I have 2 problems related to "Reply All" for sending followups to emails that I had sent:

1) When I send an email to one recipient I sometimes need to send a followup to that same person. Once upon a time I could click on that email in my Sent folder, then click the "Reply All" button in the message header panel and the reply would go to my original recipient. Now that "Reply All" button is missing and this "Smart Reply" thing refuses to give me more than a single "Reply" button which would uselessly just reply to myself. I can go to "Message"->"Reply To All" in the tools bar at the top of my window to get that functionality but that's an annoying inconvenience vs the way things used to be where there was simply a "Reply All" button next to the "Reply" button in the message header panel.

2) When I send an email and blind copy recipients I sometimes need to send a followup to that same distribution list. When I click on "Reply All" the Bcc list is stripped (this definitely was NOT the case in older versions of TB) and I'm only allowed to reply to any recipients who were NOT blind copied. To work around this I have to do Message->Edit As New Message, then cut all of the original content, re-paste it back in as a quotation, and remember to change the Subject line to prefix it with "Re:". Obviously that is ridiculously annoying vs if Reply-All simply included the Bcc'd recipients as Bcc-ed again.

It looks like both issues first showed up in 2014:

1. http://forums.mozillazine.org/viewtopic.php?f=31&t=2796815
2. https://support.mozilla.org/en-US/questions/1028980

but I can't find any reference of a fix for them.

Answer 1

2) When I send an email and blind copy recipients I sometimes need to send a followup to that same distribution list. When I click on "Reply All" the Bcc list is stripped (this definitely was NOT the case in older versions of TB) and I'm only allowed to reply to any recipients who were NOT blind copied.

This is not the behavior I see. I tested exactly this scenario in Thunderbird 60.3.0. When I am viewing a message in my Sent Items folder with a BCC in its header, and I click the Reply All button, the compose window that opens up has the BCC addresses in it. I don't know why you're seeing different behavior.

Answer 2

Changing the flag at

Tools->Options->Advanced->General->
    [Config Editor button on bottom right]->
        mailnews.reply_to_self_check_all_ident

from false to true solves both problems, don't ask me why I just found that suggestion as a possible solution to my first problem at https://bugzilla.mozilla.org/show_bug.cgi?id=1498925 and was shocked when it fixed both problems.

Update 1: the Thundebird maintainers confirmed this behavior at https://bugzilla.mozilla.org/show_bug.cgi?id=1509326. It apparently has something to do with having more than 1 account and using a common "Sent" folder for both or maybe just using a local "Sent" folder that's not under the email account where your "Inbox" sits. TB seems to behave differently when replying to Sent messages if it can vs if it can't match the email account you sent the original email from with the email account you're using now and it relies on the folders to figure out the relative accounts otherwise it relies on "reply_to_self_check_all_ident" to do some further checks... idk, it's all pretty arcane but at least there is an explanation of sorts and a workaround!

Update 2: this is going to be fixed in an upcoming release of TB, 65.0, see bug tracking id https://bugzilla.mozilla.org/show_bug.cgi?id=1511723.

Here is the Reply All excluding the Bcc when that flag is set to false:

and here is the Reply All including the Bcc when that flag is set to true: