This works until you scale the team beyond 1 person and someone else needs to decipher the 30 line awk | sed | xargs monstrosity you created. Give me a real programming language any day.

It’s perfectly normal for your computer to have daemons.

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.