[shivdeepak]

I built something similar a few months back.

link -- https://dmarcverified.com

TBH. Not very difficult to build. I am pretty much piggybacking on AWS SES's ability to provide results of all the checks for a received email.

What I found is, it really hard to make a someone send you legit emails for spam check. Usually people send one email with a sample subject line.

What I instead see is - more spam. It essentially became a honeypot. :)