BIMI

BIMI is a DNS-published standard that lets your verified brand logo appear next to every authenticated message you send in supporting mailbox clients like Gmail, Yahoo, and Apple Mail.

What it is

BIMI is a standard developed by the AuthIndicators Working Group that ties a brand logo to a domain's email identity. When a recipient opens a message in a BIMI-supporting client — Gmail on web and mobile, Yahoo Mail, Apple Mail on iOS 16+ and macOS Ventura+, Fastmail and a handful of others — they see your logo in the avatar slot instead of an initial or a generic placeholder. It's the only inbox surface where the receiver actually sees a piece of your brand before clicking.

Crucially, BIMI is not a vanity feature. It is gated by enforced DMARC, which means a domain can only display a logo if it has done the underlying authentication work. The logo is a visible reward for being a trustworthy sender.

How it works

BIMI publishes a TXT record at default._bimi.<your-domain> that points to a square SVG of your logo and, in most cases, a Verified Mark Certificate (VMC) or Common Mark Certificate (CMC) issued by an approved certification authority.

When a message arrives, the receiving server checks DMARC. If it passes with an enforced policy, the server fetches the BIMI record, retrieves the SVG and the VMC, validates that the VMC was issued for the same domain, and then renders the logo. Gmail in particular requires a VMC; Apple Mail accepts the looser CMC for unregistered marks.

The SVG itself must be SVG Tiny PS, square, with a solid background and no scripts or external references. Most brands use a tool like Entrust or DigiCert's logo studio to generate a compliant file.

Why it matters

Independent studies from Valimail and Red Sift in 2024 and 2025 measured open-rate lifts of 10 to 39 percent on BIMI-displaying mail vs the same senders before BIMI was enabled. The logo is recognised faster than a from-name in a busy inbox, which translates directly to opens and clicks.

For cold senders the calculation is different. BIMI requires enforced DMARC, and most cold-email setups run on subdomains that intentionally hold a p=none reporting-only policy. So you'll typically deploy BIMI on your primary brand domain — not the cold outreach subdomain — and let it lift transactional and reply traffic instead.

Related

• DMARC — the enforcement BIMI sits on top of
• DKIM — half of the authentication stack DMARC requires
• Sender reputation — what a verified logo helps you defend
• Cold email deliverability checklist
• How NeverSpam supports BIMI-enabled senders