The Mail folder has subfolders named after your POP accounts, and a Local Folders subfolder. The single files with no extension, and named after folders such as Inbox, Sent etc., are mbox files, and contain all the messages in a folder. If you want to import an mbox file to another computer with TB, copy it into ...Mail/Local Folders of the TB profile (while TB is closed). When you restart TB, the folder will appear under Local Folders in the Folder Pane, with the individual messages visible.

If your accounts were IMAP, the mail would automatically sync. over all devices with the same IMAP accounts.

Thanks for your quick reply. I have and ordinary mail account with a provider. I receive mails and store them on my HD. AFAIK I don't have access to a server where my mails are stored.

The structures of the folders are basically the same on both computers. As far as I understand it, the procedure you tell me to do will replace the existing mails on the iMac. Here is the history:

• On date 1 I bought a Mac Mini that I used for several years.
• On date 2 I bought an iMac and transfered everything from my Mini on it.
• On date 3 the iMac broke down so I restarted the Mini.
• On date 4 I will use my repaired iMac again.

So I want to add to the iMac all the mails I sent and received between dates 3 and 4 on my Mini while keeping the ones sent and received between dates 2 and 3. If the mails were stored in a folder instead of being packaged in a file it would be possible to manually copy the relevant ones. It would be a chore though. Hence there is no solution in the Finder.

An idea just poped up in my mind. Tell me what you think about it:

• On my Mini create new folders.
• Dump in them the mails sent and received between dates 3 and 4 that I want to retrieve.
• Copy these folders in the Library (in the Finder).
• On my iMac, paste them in the Library.
• They should appear as new folders in TB, right?

TIA Nick

If you do as you say.... Dump in them the mails sent and received between dates 3 and 4 that I want to retrieve. Copy these folders in the Library (in the Finder). On my iMac, paste them in the Library. They should appear as new folders in TB, right?

YES :)

~/Library/Thunderbird/Profiles/<Profile name>/Mail/pop account name folder Copy from pop account name folder on Mini and paste them into the iMac pop account name folder. Do this whilst Thunderbird is closed on both machines.

Thanks for your reply. Actually, when one creates a folder called MyFolder at the root in TB, in the LIbrary, in Mail/Local Folders there are

• 2 files: MyFolder and MyFolder.msf
• 1 folder: MyFolder.sbd

The subfolders MySubFolder01 etc. counterparts are just the corresponding 2 files in MyFolder.sbd. I guess I need to copy all of them. And I am done? There is no utility able to merge the content of two computers? Nick

re : 2 files: MyFolder and MyFolder.msf and 1 folder: MyFolder.sbd

Yes you need to copy all three.

'MyFolders.sbd' folder contains your 'MyFolder' subfolders and it needs the 'MyFolder' mbox file and MyFolder.msf index file so that Thunderbird knows there is a set of subfolders.

OK. Thanks. When you buy a new Mac you can use a transfer utility that imports in it all your stuff from your old Mac. I guess there is the same thing in Windows. If you have a Mac and buy a PC is there a ute that allows you to import your TB and FF stuff in it? Nick

The entire Thunderbird folder can be copied from one computer to another:

https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer

On the left, under Editing Tools, select the appropriate operating system. A similar process works for Firefox, i.e. copy the ...\Roaming\Mozilla\Firefox folder.

With TB, the only additional item to know when moving between OS X or Linux and Windows is to delete the pkcs11.txt file from the target computer's profile folder, to avoid password issues.

OK. Thanks for your input. Nick

sfhowes said

The entire Thunderbird folder can be copied from one computer to another: https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer On the left, under Editing Tools, select the appropriate operating system. A similar process works for Firefox, i.e. copy the ...\Roaming\Mozilla\Firefox folder. With TB, the only additional item to know when moving between OS X or Linux and Windows is to delete the pkcs11.txt file from the target computer's profile folder, to avoid password issues.

I looked at this procedure and its fairly simple from one Mac to another yet it doesn't talk about doing the same from one Mac to a PC. Nick

Copy the Thunderbird folder on the Mac and paste it into this location on the PC: C:\Users\<winusername>\AppData\Roaming

Delete any existing Thunderbird folder in Roaming before pasting the one from the Mac. Before starting TB, delete pkcs11.txt from the profile folder in ...\Roaming\Thunderbird\Profiles\<8charstring>.default

This page explains the Windows end of the transfer.

Thanks for the tips. It seems fairly simple. Yet it's strange there is no tool to automate it. Nick