The number is real you guys

None of these words are in the Bible

You should definitely set up a DMARC record to prevent other people from using your email domain to send spam. If you don’t have DMARC configured, other email servers will give any senders the benefit of the doubt and accept mail that claims to be from your domain.

You can just set the DMARC record to reject 100% of unverified mail and call it a day. Since you aren’t sending anything it won’t affect you.

It’s the greetings of a heathen, Heathen’s Greeting. Totally acceptable usage.