This happens every couple of months. All my tags on the 11,000 emails are removed and I need to start again from scratch tagging emails.

Do you have more than 5 tags? Or 10? If not, tags should not be lost because most imap servers support tags.

firefox.mc15c said

This happens every couple of months. All my tags on the 11,000 emails are removed and I need to start again from scratch tagging emails.

Do you have more than 5 tags? Or 10? If not, tags should not be lost because most imap servers support tags.

I have over 50 tags, however they do not sync to the server. I use ProtonMail, but it does not seem to support syncing tags. The tags I am referring to are only in Thunderbird. I appeared that all the messages get reset, and they downloaded again from the server.

The proton mail bridge is an IMAP mail server installed on your local computer. You synchronize to it every time you get mail.

In the case of an IMAP server the tags are stored on the IMAP mail server, unless the server simply does not support tags. Does proton support tags? I have no idea. I am not a customer.

The bridge development site lists quite a number of issues, many Thunderbird specific. https://github.com/ProtonMail/proton-bridge/issues

I do know that Thunderbird makes no attempt to preserve data stored in the folder index.database when a folder repair occurs, it might even extend to a compact. So if the bridge is forcing Thunderbird to store tags locally You will loose them on each repair, and perhaps compact.

Ohh I forgot the bug link https://bugzilla.mozilla.org/show_bug.cgi?id=1568355

“In the case of an IMAP server the tags are stored on the IMAP mail server, unless the server simply does not support tags. Does proton support tags? I have no idea. I am not a customer.” I know there’s tags on the Proton Mail servers, because whenever I tag messages on the web server, they come through to ThunderBird as new folders on the account. However, the tags I apply in Thunderbird do not go back through proton bridge. I think you’ve hit now in the head that when the folders repair is when the tags are stripped off, I’ll write a message to proton to see if the Bridge can store the tags.

Is there a place in the logs where I can look to see if the folders have been repaired and confirm that this is the problem?