20.04.2 LTS lost all Emails with update to Thunderbird 86.0

[janvi2]

LTS automatic update mechanism updated my Thunderbird Mail client to 86.0. Probably for this reason, all my Emails disappeared. Invoking Thunderbird now, welcomes me to setup any existing email account. There is button „Import“ but this does not find the own accounts nor its Emails from previous thunderbird version. Examining the files, old emails should still exist but I dont know how to retrieve. Probably they are stored in
/home/jv/snap/thunderbird/common/.thunderbird/18g404is.default

/home/jv/snap/thunderbird/common/.thunderbird/m7bd5ck2.default-beta

Rename of the default to default-beta name ends in a neckish html error message after invoking thunderbird why I tried to dig down the dirctory further. There I found a mail subdir with the 4 subdirs of my previously used mail accounts using postfix number 1-4.

18g404is.default/mail/pop.1und1-1.de

18g404is.default/mail/pop.1und1-2.de

Already tried to copy the complete mail directory within subdirs to the default-beta. There was no such dir there before and manually copied dir is not accepted (or nothing happens when invoking thunderbird). What to do to retrieve the old emails (at least from one account) preverably within the login setup data? If no solution, how is possible to go back to previous thunderbird installation ?

[Hagar Delest]

That's the kind of event that keeps me away from snap builds.
In the past, when I used beta versions, I used to install the tarball from the Thunderbird site (merely unzip it in /opt and set a custom .desktop file) so that it uses the standard profile in /home. And that profile was backed-up periodically.

If you had an IMAP mail account (very likely), you can retrieve all your mail from the mail provider server anyway (that's the point of IMAP). Just recreate the account in TB and it will fetch the last content of the account.

Perhaps you can get the previous snap version somewhere.

[rsteinmetz70112]

You may need to start the profile manager and point Thunderbird to your old profile. If you don't know where it is you can search for "Mail" which should have you old email in it.

[janvi2]

finally I was able to retrieve old emails after setup and entry of new mail access data. Seems Thunderbird needs this to generate the directories with its index. After I was able to move the old files from subdirectory and the content was accepted. Thunderbird seems to be a ideal application to loose old mails frequently and Google shows many desperate users. Assume all, this is not what I expect from user friendly program. Click to a html link inside a mail, Thunderbird as a Mozilla project cannot find its own Firefox Browser what was working before. Furthermore it seems not possible to convert a pop account into imap after started once.