What we tested
Probed live on 23 Aug 2026 against rubric v1. 2 of 5 checks passed.
PROBE-VERIFIEDtier 2 of 3
✓Markdown negotiationAccept: text/markdown
—Markdown twin at a predictable URL/page.md
—llms.txt/llms.txt
✓API catalogRFC 9727
—MCP server answers/.well-known/mcp/server-card.json → tools/list
What an agent could do here
Read from the page’s own content, with the wording each was drawn from. Inference is kept separate from tested facts — an agent completing the action is tier 3.
UNVERIFIED
register“Demo: https://email-check.app/try”https://email-check.app/try
query_api“Real-Time API”
Context
5 sites in the index share the category email validation api, of which 2 are transactional.
How we grade
Three tiers. Every listing shows which one it has reached, and when. The rubric.
tier 1Declared
The site says agents are welcome in its robots.txt. A permission, not a capability.
tier 2Probe-verified
We fetched the site and tested each signal ourselves. Dated, repeatable, re-checked on a schedule.
tier 3Behaviourally verified
An agent completed the action end to end — booked, bought, submitted — and it worked.
Own this site?
3 checks did not pass when we last looked: Markdown twin at a predictable URL, llms.txt, MCP server answers. Each is a small, specific fix; the rubric says exactly what we look for.
Behavioural verification — an agent completing your booking, purchase or contact flow end to end, with the date published here — opens to a small founding cohort first. Leave an email to be in it.
Related verified sites
DeBounce APITechnical overview and documentation of the DeBounce email validation API for developers.
email validation api Cleariflow APICleariflow API provides an email validation service that checks email deliverability, form
email validation api Sanitize Email API DocsDocumentation for Sanitize Email API providing email validation, SMTP verification, bulk p
email validation api ValidKitValidKit provides a real-time email validation API with under 200ms response times for sig
email validation api VibeMarketologRussian AI marketing platform offering agents for advertising, analytics, and sales with 2
ai marketing platform AigonAigon provides AI agents focused on productivity, education, property, and facilities mana
ai agents platform BibiGPTBibiGPT is an AI tool that summarizes and transcribes audiovisual content from multiple pl
ai video summarization tool MewayzMewayz is an all-in-one business management platform offering over 144 modules including C
business management platform Record generated from a live database query. Method: about the index.