BIMI checker

What BIMI is for

Brand Indicators for Message Identification lets a domain publish a logo that some mailbox providers display next to authenticated email from it - a visual trust signal, not an authentication mechanism itself. It is layered entirely on top of DMARC: BIMI does nothing for a domain that has not already deployed DMARC at enforcement.

The DMARC prerequisite

Every major BIMI-supporting provider requires the domain's DMARC policy to be at p=quarantine or p=reject - not p=none - before it will consider showing the logo at all. This is checked here using the same DMARC service (including its organizational-domain tree walk) as the dedicated DMARC checker.

What is checked, and what is deliberately not

• Record syntax - the BIMI TXT record at selector._bimi.domain and its l= (logo) and a= (certificate/evidence) tags.
• Resource fetched - whether the logo URL actually responds.
• SVG checked - a shallow well-formedness look, not full validation (see the SVG validator for that).
• Certificate reference discovered - whether an a= tag is present at all.
• Certificate validated - never performed. Confirming a BIMI VMC/CMC actually chains to a trusted CA requires certificate-path validation this tool does not implement, and it says so rather than implying otherwise.

Passing every check above does not guarantee any specific mailbox provider will display the logo - each provider applies its own additional acceptance rules.