What it is

Brand Indicators for Message Identification is a DNS record pointing at your logo. Participating receivers — Gmail, Yahoo, Apple Mail and others — display that logo next to your messages in the inbox rather than a generic avatar or an initial.

It lives at default._bimi.yourdomain.com and points to an SVG file, plus optionally a certificate proving you own the mark.

The prerequisites

BIMI does nothing until DMARC is at quarantine or reject. This is deliberate — the logo is a trust signal, so it is only granted to domains that have actually locked down who can send as them. p=none domains get nothing.

The logo itself must be SVG Tiny Portable/Secure, a restricted profile of SVG. A standard export from a design tool will usually be rejected and needs converting.

VMCs and whether you need one

Gmail requires a Verified Mark Certificate — proof from a certificate authority that you own the trademark — before it will display your logo. VMCs cost real money annually and require a registered trademark. Some other receivers will display a BIMI logo without one.

For cold email specifically this is rarely worth it. Your secondary sending domains are not brands anyone recognises. BIMI is worth the effort on your primary domain, where recipients already know who you are.

The record and the logo

The BIMI record is a TXT at default._bimi.yourdomain.com reading v=BIMI1; l=https://yourdomain.com/logo.svg; a=https://yourdomain.com/vmc.pem. The l= tag points at the logo, the a= tag at the certificate, and the a= tag can be empty if you have no certificate. The record does nothing unless the domain's DMARC policy is quarantine or reject — and for the organisational domain, the subdomain policy sp= must not be none either.

The logo is the part that fails. It must be SVG Tiny 1.2 in the PS profile: square, centred, a solid background, no scripts, no external references, no gradients or embedded rasters, and a <title> element. A normal SVG export from a design tool almost never validates as-is. Convert it, then run it through the BIMI checker, which validates the SVG profile as well as the record. The BIMI generator writes the record once the logo is hosted.

Where the logo shows

Yahoo Mail displays the logo from the record alone. Gmail displays it only when the a= tag points at a Verified Mark Certificate (VMC) or a Common Mark Certificate (CMC); with a VMC it also shows a blue checkmark beside the sender name. Apple Mail displays it with a VMC. Outlook does not support BIMI at all, in any form. So on a B2B list that reads in Outlook, BIMI is invisible to most recipients; on a consumer or startup list that reads in Gmail, it shows, if you have paid for the certificate.

A VMC requires a registered trademark on the logo and runs to four figures a year. A CMC does not require a trademark — the logo needs to have been in use for a year — costs less, and gets the logo into Gmail without the checkmark.

Is it worth doing on a cold email fleet?

Usually not, and the reason is not the display. BIMI is per organisational domain and certificates are issued per domain, so a fleet of thirty secondary domains would need thirty records and, for Gmail, thirty certificates. Nobody does that. Where BIMI earns its place is the main company domain — the one that sends replies, follow-ups from real people, and anything the prospect will see after the first contact — where one record and one certificate cover every mailbox.

The part that is worth doing on every domain, fleet included, is the prerequisite: DMARC at enforcement. A domain that qualifies for BIMI is a domain whose authentication is right, and that is the reputation signal receivers actually score. The DMARC checker tells you whether a domain is there yet.

Check yours

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Common questions