Hi HN, I got tired of manually unrolling nested SPF includes to figure out which vendors are actually authorized to send email on a domain. Most checkers just give syntax validation or Pass/Fail.

I built SPF1 to instantly resolve the cryptic includes (_spf.google.com, etc.) into actual vendor names (Google, Mailchimp, Proofpoint) to easily spot unauthorized 'Shadow IT'.

It's designed to be stupidly fast (<50ms). No ads, no signup walls, just a raw lookup. Would love feedback on any major vendor signatures I might have missed.