A logo is a trust signal, and BIMI's design reflects that

BIMI exists to show a brand's logo next to their authenticated email in a supporting inbox — but a logo next to a message is a strong trust signal, so the standard was deliberately designed to make it hard to get without first proving legitimate control over the sending domain's email infrastructure. That's why BIMI has real prerequisites beyond just publishing a TXT record: strong SPF/DKIM alignment and, critically, DMARC enforcement — a policy of quarantine or reject, not just monitoring with `p=none`. A domain that hasn't locked down its own email authentication has no business showing a trusted logo, and the spec's prerequisites reflect that reasoning directly.

Why the VMC (a=) tag matters so much in practice

A Verified Mark Certificate is a third-party-issued certificate that cryptographically attests the logo actually belongs to a legally registered trademark held by the sending organization — without one, most major inbox providers (Gmail among them) simply won't display the logo at all, even with a perfectly valid BIMI record and enforced DMARC otherwise in place. That makes the `a=` tag the single most common reason a technically correct BIMI setup doesn't actually result in a visible logo: the record is valid, DMARC is enforced, but no VMC was obtained, so nothing shows up. Checking for that tag specifically is often the fastest way to explain "why isn't our logo showing" when everything else looks right.