Re: Spam rule for HTTP/HTTPS request to sender's root domain

[Mike Marynowski]

Just one more note - I've excluded .email domains from the check as I've 
noticed several organizations using that as email only domains.

Right now the test plugin I've built makes a single HTTP request for 
each email while I evaluate this but I'll be building a DNS query 
endpoint or a local domain cache to make it more efficient before 
putting it into production.