Thunderbird Tips: adding many tags

Tag Toolbar acelerates use of tags in Thunderbird. However, there is one precaution for adding many tags to a message. Attached tags are stored in X-Mozilla-Keys header and a summary file whose file extension is *.msf. The most important fact is the length of the header is limited to 80 bytes. If the sum of lengths of attached tag keys exceeds the limit, overflowed tag keys are stored only in the summary file. Namely, the overlowed tags will disappear if you remove or rebuild the file. For example, if you rebuild a summary file by clicking "Rebuild Index" button in Folder Properties form, overflowed tags in the folder are all gone.

In order to avoid the issue, I suggest two tips. One tip is to make tags whose keys are short. If you create a tag named "long long tag name", its key will be "long_long_tag_name". It costs 18 bytes. If you create a tag named "a" and rename it to "long long tag name", its key is still "a" in spite of its long name. You can save 17 bytes by the latter way.

Another tip is to compact folders. If you compact folders by File->Compact Folders etc., mail data is reconstructed. During the reconstruction, the X-Mozilla-Keys is also reconstructed and all tags are stored in it, exceed the 80 bytes limit. Once all tags are stored in the header, it is OK to remove/rebuild the summary file. However, there is one note for it. The reconstruction will be conducted on the folders in which the messages are removed or moved.

I'm glad you could enjoy tagging messages with these tips and Tag Toolbar.