Thunderbird Archiving
Posted by on 7 Oct 2021 16:23

Problem: When archiving from Thunderbird the archive content does not match the Thunderbird profile content.

Background: Thunderbird does not have an API, that can be used to acces the profiles and accounts. MailStore has to search for the profile directory on the local drives and has to analyze to files found there. Thunderbird stores message of each folder in mbox files. This is a container format which can hold multiple e-mail messages. Some folder and message information are stored in Mork database files with the file extension MSF, which are not read by MailStore.

Workaround: Archive message directly from the e-mail server. The IMAP protocol should be preferred.

Symptom: No messages will be archived at all.

Thunderbird supports two message store types which define how messages are stored on disk. The mbox type and the newer maildir type. MailStore only supports archiving messages from accounts that are using the mbox message store type. The store type used can be viewed in Options > Account Settings > Account > Server Settings > Message Store > Message Store Type. The message store type an account uses cannot be changed in hindsight.

The message store type for new accounts can be set in Options > Advanced > General > Advanced Configuration > Message Store type for new accounts.

Symptom: Some folders are missing in the archive.

Only messages in folders that have been stored locally by Thunderbird can be taken into account when archiving. To check this in MailStore you can open the properties of the archiving profile > Next > Folders > Show Effective Folders. Folders displayed in grey are not stored locally and cannot be archived. To check this in Thunderbird navigate to Options > Account Settings > Account > Message Synchronizing and verify that Thunderbirds keeps messages on this computer.

Are folder missing in Thunderbird that should be there, e.g. are visible in the webinterface of the provider, verify that in Options > Account Settings > Account > Server Settings > Advanced the option Show only subscribed folders is disabled.

Empty folders will not be synchronized into the archive. In case empty folders do have subfolder which do have messages, the filled subfolder may not be sychronized. To avoid this, move at least one message into the empty base folder.

Symptom: Folders do have the wrong name in the archive.

In case an IMAP folder name contains non ASCII characters, these characters must be encoded in modified UTF-7. Thunderbird uses these folder names with the encodeded characters as file names of the mbox files on the file system. MailStore uses the file names of the mbox files as folder name in the archive.

Local folders in Thunderbird that contain special or non-Latin characters that cannot be used as filenames in the file system may have a different name in the archive. The chosen foldername is only stored in the Mork database file which is not read by MailStore and MailStore is only able to read the replacement name from the file name.

Root folder names of local folders that contain special or non-Latin characters are not shown correctly.

Symptom: Moved messages are not moved in the archive.

When messages are moved in Thunderbird, a copy of the message will be created in the target folder and the source message will be flagged as removed in the Mork database of the source folder. The source message itself remains in the mbox file but is not shown by Thunderbird anymore. Since MailStore does not read the Mork database file, it is not able to detect the moving of the message and skips the message in the new folder. MailStore only archives one appearance of each message per source.

In Thunderbird folders can be compacted by right clicking on a folder and selecting Compact. Moved messages then will be removed from the mbox file and MailStore is able to detect the moving of the message.

Article-ID: KB20161103-0-EN (Deutsche Version)

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