The rule

Send people only the thing they asked for.

Consent: Every message ties to a list, and every subscription keeps the exact words the person agreed to, with the time and the address.
No cold outreach: No purchased lists, and no owners on people. Deals have owners; people do not.
Unsubscribe: One click on every email. An automation cannot email anyone who is not subscribed to its list, whatever it was told.