You did not explain the details. The screenshot looks like the contents of the thunderbird folder. did you paste it into c:\users\<yourid>\appdata\roaming while thunderbird was not running? Did you get prompted immediately to create a new account? Knowing that will help. Are you wanting to retrieve message folders for a POP account or from Local Folders? Thanks

Hello David, thanks for your questions and your reply. Local folders from a data backup (from an SSD) of POP3-mailboxes (three pieces) were copied to the target directory ".thunderbird". Immediately after that, I restarted TB and got the setup dialog for setting up a mailbox/create a new account. For me the signal that the "superated" of the old mailboxes did not work. They are not visible in the other tab of the TB either. Maybe you need to rewrite the ini-file to drag the right folders? Best greetings

Holà, Offenbar benutzt du Linux. POP oder IMAP? Einfach nur Postfächer (Accounts oder Konten) übertragen ist nicht die einfachste Methode zur Migration der Thunderbird-Daten von einem PC auf einen neuen PC. In der Regel ist es am einfachsten, den Ordner Thunderbird bzw .thunderbird (unter Linux) vom alten PC auf den neuen zu übertragen und bei beendetem Thunderbird im entsprechenden Verzeichnis einzufügen. Eine andere Möglichkeit wäre, das zuletzt benutzte Profil (bzw. den Profilordner) vom alten PC zu kopieren, auf dem neuen PC im Verzeichnis .thunderbird einzufügen und dann mittels des Profil-Managers neu einzubinden. Wenn dein Screenshot die neue Installation anzeigt, dann fällt auf, dass sie vier verschiedene Profile enthält. Es ist völlig unklar, welches das aktuelle Profil ist. Falls du nur die Profilordner vom alten auf den neuen PC übertragen hast, dann kann das nicht funktionieren, denn TB befragt beim Start die profiles.ini Datei um zu wissen, welches Profil zu öffnen ist. Wenn du also die profiles.ini nicht vom alten PC kopiert und in .thunderbird eingefügt hast, klappt das nicht.

If the intent is to move message folders to Local Storage, that may be insufficient for thunderbird to identify the profile. That is, if you successfully place message folders in the Mail\Local Folders folder of a new profile, thunderbird looks to see if there is an account. If not, I believe it creates a new profile. So, my suggestion is to add an account prior to copying those folders in. This is not in disagreement with @Mapenzi, as that individual provides excellent advice; the issue may be no understanding exactly what your full intent is.

Hola @Mapenzi! Hello @David!

The problem is solved "almost", but...

Now I only miss the self-created folder-structure within one of the mailboxes. In the profile subtree that i haved copied, I find the missed folders under "Archives.sdb", but they are not displayed in the corresponding mailbox. SDB looks like a database? How do I reconnect it?

In the settings of TB, there is an "archive function", but it doesn't have anything to do with the "Archives.sdb" in the folder structure of the .thunderbird directory, right?

Would I be pleased if you had an idea/solution for the last step? Thanks in forward.

My fault with the profiles was: I had only copied/inserted the explicit profiles from the old TB under the new one, without the *.ini's.

However, i had A) removed the new .thunderbird directory in the personal area and B) substituted it by the old .thunderbird. Ready. For me, this did not come out of the instructions.

Ciao

Now I only miss the self-created folder-structure within one of the mailboxes. In the profile subtree that i haved copied, I find the missed folders under "Archives.sdb", but they are not displayed in the corresponding mailbox. SDB looks like a database? How do I reconnect it?

The .sbd folder corresponds to a folder with subfolders in Thunderbird. So it contains the mboxes of the subfolders. Please verify if there is an "Archives" file (without extension) together with the "Archives.sbd" folder. If it misses you have to create it with a text editor. Your system will add the extension .txt to the new file, you'll have to delete the extension .txt.

To the rest of your message I'll reply later