What is stored in AppData\Local\Thunderbird, and do I need that folder to restore my Local emails?
I just want to confirm [referencing https://support.mozilla.org/en-US/questions/1280939 ] that I am understanding correctly:
I have an IMAP account, and some of my emails have been downloaded from IMAP to local Thunderbird folders.
Now I am going to be migrating my TB data from one computer to another.
Is it correct that I only have to back up and restore my AppData\Roaming\Thunderbird folder -- and that this will restore my locally saved emails as well?
If the answer is yes, just out of curiosity, what kind of data is stored in the AppData\Local\Thunderbird folder?
And is there any scenario in which it becomes useful or advisable to back up and restore that folder as well?
Alla svar (4)
re :I have an IMAP account, and some of my emails have been downloaded from IMAP to local Thunderbird folders.
Imap accounts can only show what is on the server. All imap folders will also be on server and you subscribe to see them, although all default folders will auto subscribe eg: Sent, Inbox, Spam etc. Imap account synchronise with server to download either headers or full copies of emails. You could say the imap folders and the server folders are basically one and the same. You cannot assume any imap folder as being a 'local folder'. Imap folders are not independent copies because they synchronise with server.
This means if you were to logon to webmail or use another computer or phone to access the same email address via imap and delete some emails, you would find those emails will automatically be deleted from the imap account in Thunderbird.
Benefit: this means if you needed to recreate an imap account, you would find it is exactly the same because everything is stored on server.
Imap folders can download headers or full copies and this can be set up to be different for each folder. When headers are downloaded and you select to view an email, it is retrieved from the server and held in a temp folder to failitate viewing. If you went into offline mode, then you would see the headers as displayed in the list of emails, but if you select to view email then it will be blank because being offline there is no internet connection with server, so nothing can be downloaded. If you download full copies, then they would still be visible even in offline mode as a full copy is held within Thunderbird.
Some people like to only download headers because it uses less space on harddrive. Imap offers various options on how much to download.
To create a good copy of emails, so you have a backup - (after all if everything is on server and you lose emails in imap folders then you will lose them off server as well. It is not a good idea to only rely on the server as the only copy) - make sure you have all the correct set up to fully synchronise all folders to get full copies of emails downloaded and not just headers. Please read this info to ensure you really have got correct settings to download full copies for all folders.
Only emails stored in the 'Local Folders' mail account can be considered as 'local folders' because they are independent of any server. Pop mail account folders do not synchronise with server and so those pop account folders can be considered as a 'local folder'.
I would recommend that you do perform a backup periodically, as having only the one copy on the server is not without it's risks.
re :Is it correct that I only have to back up and restore my AppData\Roaming\Thunderbird folder
Providing you have downloaded full copies of all emails in all accounts, you only need to backup/copy the 'Thunderbird' folder. This will then create a copy of everything.; profiles, accounts, emails, filters, address books etc etc.
re :what kind of data is stored in the AppData\Local\Thunderbird folder? Windows keeps a local copy of the cache to facilitate functionality, but it does not contain any emails etc. You do not need to copy anything from that location. Thunderbird is not using it.
Thanks for your detailed and helpful response!
RE: "Only emails stored in the 'Local Folders' mail account can be considered as 'local folders' because they are independent of any server. Pop mail account folders do not synchronise with server and so those pop account folders can be considered as a 'local folder'."
Yes, those are the email folders I was wondering about. So emails stored in those 'Local Folders" are also contained in the AppData\Roaming\Thunderbird folder? Correct?
re :So emails stored in those 'Local Folders" are also contained in the AppData\Roaming\Thunderbird folder? Correct?
Correct. They are stored here in mbox files. AppData\Roaming\Thunderbird\Profiles\'profile name'\Mail\Local Folders mbox files are text files which do not have any extension. They have the same name as the folder. Emails are added to the text file, one after the other in the order downloaded/added. So they are not stored in separate files.
@Toad-Hall, thank you so much for the further clarification. Very appreciated!