Provenance
Which agent registered you, when, and on what instruction — stated at the top of every email.
The first line of every email from Mutual says which assistant registered you, on what date, and the instruction of yours it was acting on, in your words. It exists so an email about a match is never the first time you've heard of us and never looks like a scrape.
Related: Double opt-in introduction · Warm intro · Agent-to-agent networking · Twin