Gmail emails automatically going to Trash

Mail from certain senders, including important ones, skips my Gmail inbox entirely and appears already sitting in Trash. Nothing I did knowingly.

What machinery sends mail straight to Trash and how do I audit all of it?

Only a few mechanisms can trash mail on arrival, so a short audit covers the lot. In order of likelihood:

1

Filters first, the overwhelming cause: Settings gear, See all settings, Filters and Blocked Addresses. Read every filter for the Delete it action, including filters whose match criteria are broader than they look, a filter on a common word trashing far beyond its intended sender. Delete or edit the guilty ones, and check the Blocked Addresses list on the same page since blocking a sender routes them to Trash quietly.

2

Other access second: Settings, Accounts and Import for delegated access to your account and myaccount.google.com under Security for third party apps and connected devices with mail scope. An old cleanup app or an inbox tool with delete permission behaves exactly like this, revoke anything unrecognized.

3

POP clients third, the sneaky one: a forgotten desktop or phone client fetching over POP with its own delete after download behaviour, governed by Settings, Forwarding and POP/IMAP where the POP option chooses what happens to fetched mail. Set it to keep Gmail's copy or disable POP if nothing should be fetching.

4

Recover the casualties while auditing: Trash holds mail for 30 days before permanent deletion, so search in:trash from the important senders now, select and Move to Inbox, the audit and the rescue in one sitting.

When every mechanism above audits clean and the trashing continues, capture one victim's details from Trash, sender and exact time, then recheck the filter list for recently created entries, since a filter appearing that you did not create moves the conversation to account compromise: password change, security checkup and sign out of all sessions the same hour rather than the same week.

A filter from 2019 matching the word invoice, created for one noisy sender and trashing every invoice since. Deleted it, rescued 20 messages from Trash including the important ones. The audit list is saved for the next mystery.