[Thunderbird] Archive Email Locally Action

[zigzag]

The Archive Email Locally action that copies an email to a local folder and deletes it from the server (freeing up storage space on the server). 

Free email server storage is often limited (typically 5–15 GB), while many users have over 1 TB of available space on their computers. 

This action differs from standard Archive feature, which archives an email on the server. Archive Locally should perform delete operation on the server, after copying email to a local archive folder.

Some email providers, such as Gmail, have non-standard IMAP implementations where deleting an email from the Inbox folder does not actually remove it from the server. For these providers, Archive Locally should perform all necessary steps to ensure the email is fully removed from the server. In the case of Gmail, Thunderbird would need to delete the email first from the Inbox folder, then from the All Mail folder and finally from the Trash folder.

In my experience, Thunderbird users often want to free up server storage by deleting or archiving emails in Thunderbird and are surprised, when they don't gain any additional free storage on the server.

The Archive Locally action would provide Thunderbird with an unique value proposition, compared to web-based email clients: the ability to free up server storage while preserving messages in a local archive folder.

[Jon]

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[DanV]

This would be an excellent and valuable feature to have

[stapldm]

Note that the user needs to make a config change to the GMail server settings before anything ThunderBird could possibly change would work.

tldr; Google mail server config prevents email client deletions by default. Changes below allow Archive to Local behaviour in TB as long as you archive from GMail's All Mail folder.

With the existing Archive function [TB version 140.12.1esr] if this config change isn't made, GMail prevents full deletion via anything other than the webmail interface. The Local Folders simply get a copy of the email, and the server retains the original (deletes locally from the inbox then re-appears when TB re-syncs the inbox from the All Mail folder, the true mail store ).

After I made the changes below, the existing Archive function appears to work as I require, though I manually archived from the All Mail folder rather than the inbox to achieve this; I stopped experimenting at this point, so other options may be workable.

From Google:

AI Mode conversation: gmail keeps resurrecting deleted emails
... much back and forth conversation removed ...

Gmail treats emails differently than standard email providers because it uses labels instead of actual folders. When you delete an email in Thunderbird via IMAP, Thunderbird defaults to just removing the "Inbox" label, leaving the email completely untouched in your "All Mail" archive. To the server, the email is still active, causing Gmail to push it right back into your inbox on the next sync.
Fix this behavior by updating settings in both Gmail Web and Thunderbird:

Step 1: Change Gmail's Server-Side IMAP Behaviour
By default, Gmail blocks external apps from deleting emails permanently. You must explicitly give Thunderbird permission to move items to the trash.

1. Log into your account on the Gmail Web Client.
2. Click the Gear icon (top-right) and select See all settings.
3. Click on the Forwarding and POP/IMAP tab.
4. Scroll down to the IMAP access section.
5. Under "When a message is marked as deleted and expunged from the last visible IMAP folder:", select Move the message
6. Click Save Changes at the bottom of the page.

Step 2: Map Thunderbird's Trash to Gmail's Trash Folder
Next, point Thunderbird to the exact folder where Gmail expects deleted mail.

1. Open Thunderbird.
2. Right-click on your Gmail email address on the left pane and select Settings.
3. Under your Gmail account, click on Server Settings.
4. Look for the section: When I delete a message.
5. Select Move it to this folder.
6. Use the dropdown menus to map it to: [Gmail] -> Trash (or Bin, depending on your regional language settings).