Inspect receiving rules

Shows the inbox's blocked senders. With enabled: true, mail whose From address matches an entry in addresses or domains does not arrive, and no copy is kept. With enabled: false nothing is blocked, and the saved lists stay. Mail already received isn't affected by a change.

Entries match as in sending rules.

The From address is written by the sender and isn't authenticated, so these rules stop unwanted mail from a sender, not a sender who forges another address. They can be changed only in Account → Receiving rules, not through the API. Receiving rules guide