Deleting mail can affect server storage or only a local folder, depending on the account type and folder location. Understand that difference before a large cleanup so you do not remove the only copy of important business records.
IN THIS ARTICLE
Prepare for the change
Identify whether the selected folder belongs to the IMAP server or Local Folders. Choose one unimportant message for the initial test and preserve required business records before permanent deletion.
01 Delete and recover email in Thunderbird
- Confirm the account and folder in the folder pane. Identify whether it belongs to the IMAP server or Local Folders.
- Delete one harmless test message using the normal Delete control. Open Trash and check where the message went.
- For an accidental deletion, move the message back while it is still present in Trash. Confirm the recovery in webmail for an IMAP account.
- Review required records and backups before emptying Trash or using permanent-delete options.
Confirm the expected result
Check webmail and the mailbox usage after synchronisation. If the aim is to reduce quota, remember that Trash and Sent may still count until the server's cleanup is completed.
If the change does not work
Folder compacting is different from archiving or creating a backup. A missing message may also be hidden by filters or moved by another client. Search the account and inspect folder location before assuming the data was permanently removed.
A common question
Are messages under Local Folders backed up by my hosting account?
No. Local folders live on that computer unless you copy them elsewhere. Include them in your device backup plan and secure a copy before rebuilding Thunderbird or replacing the computer.