Google Mail follows the philosophy, to archive all deleted messages instead of erasing them forever. Especially for confidential messages this is a bad behaviour, and typically everyone who deletes something wants it deleted and not archived. Now, how do I delete all those automatically archived messages in Google Mail?
You cannot easily find a filter for that, but with advanced search terms, there is a solution to that. Go to your Gmail online account and select the search field.
- Enter “-in:Inbox” and add all other labels that should not be deleted, such as “-in:Important-Mails -in:Family-mails -in:Sent“.
- You may want to only include only older mails, thus add “before:2008/12/31“, altogether then something like:
-in:Inbox -in:Sent -in:Important-mails before:2008/12/31
This way Gmail should show all archived mails, now select all of them and delete them. Forever.
P.S.: This also helps to keep your mailbox within the maximum mailbox size quota.
P.P.S.: There is a Labs feature you can turn on that – at least – moves all mails that are deleted within the web interface to Trash instead the archive. It is called “Advanced IMAP controls”.