SMTP TLS Reporting, policy viewer
For an easy way to lookup a domain’s SMTP TLS Reporting Policy try my nice MTA-STS Policy Viewer.
After writing the first notes on SMTP TLS Reporting I thought it would be nice to see all setting on one page, without using multiple tools and lookups for DNS and HTTPS data. The first iteration was a shell script, and the second iteration was a Python function. With some more fiddling I set it up as a Google Cloud Function, with a simple web frontend.