Allow Thunderbird to archive proton emails

If you get a Operation Not Allowed error when archiving emails in Thunderbird when using Proton Bridge, try to update your account settings in Thunderbird.

1. Open Settings.
2. Open Account Settings.
3. Select your bridge account.
4. Open Copies & Folders.
5. Go to the Message Archives section and select your archive folder in Proton.

Thank you years old reddit question and the reply from ProtonMail.

2026-04-03