Mind sharing your filter rules? KnowBe4 uses X-PHISHTEST header and I think I saw Proofpoint using something similiar a few years back

Straight from the source: https://help.proofpoint.com/Proofpoint_Essentials/Security_A... xD

The vast majority of security controls are designed for the careless and the clueless.

My IT department use the official Microsoft phishing test. The emails arrive in inbox with 0 headers. (There's also a helpful Microsoft page of all the dodgy sounding domains they've registered for this.)

I did this and it worked for a few months before word got to security who then forced everyone to remove the rule.

I just don't check my emails anymore. If it is important, people will complain on teams that nobody answer with some sort of urgency and then I'll look for it specifically.