wildcard
If you’re an ESP with small customers you may have looked at the recent Google / Yahoo requirements around DMARC-style alignment for authentication and panicked a bit. Don’t impersonate Gmail From: headers. Gmail will begin using a DMARC quarantine enforcement policy, and impersonating Gmail From: headers might impact your email delivery.…For direct mail, the domain in the sender’s From: header must be aligned with either the SPF domain or the DKIM domain. This is required to pass DMARC alignment. So everyone who’s using their gmail address to send bulk mail is going to have to stop doing that within the next few months if they still want their mail to be delivered. For any ESP customer that already has, or can be convinced to buy, a domain for their web presence maybe they can be persuaded to switch to using that – though even if they can, onboarding 100,000 technically naive users