- Sent mail to a file; used "!unsubscribe".
- Sent mail to a legalpad document; used "!unsubscribe".
- Sent mail to a task; used various "!close", "!claim", "!assign", etc.
- Sent mail to a paste.
- Sent mail to a revision; used various "!reject", "!claim", etc.
- Tried to send mail to a pull request but it's not actually reachable.