How can I permanently delete messages from gmail?

Question

For privacy reasons, I want to permanently delete a lot of mail from gmail. I've downloaded it using IMAP. However, when I try to delete the mail, it keeps coming back. This happens even when I delete from the All Mail folder. I would rather not go in through the gmail interface, as I have 50,000+ email messages. Is there another way?

Answer 1

You'll have to open the web interface to change the settings anyway, so you may as well use the web interface to delete your messages. If the messages you want to delete have anything at all in common, just use Gmail's powerful search tool to find them, select all, and delete.

Answer 2

Using OfflineIMAP to sync IMAP folders 2-way, I haven't got many issues about mails coming back (it does happen once in a while, but that's very rare).

I just tried deleting mails on my Gmail account, it works like a charm (deleting them locally, they're removed from the online interface).