Authentication

BIMIBrand Indicators for Message Identification

Definition

BIMI (Brand Indicators for Message Identification) is a standard that displays your brand logo next to authenticated email in supporting inboxes like Gmail, Apple Mail, and Yahoo. It is a reward layer on top of DMARC: you only qualify once your domain enforces DMARC, publishes a special BIMI DNS record pointing to an SVG logo, and, for Gmail and Apple, proves you own that logo with a VMC.

  • Shows a verified brand logo beside authenticated mail in supporting inboxes
  • Requires DMARC at enforcement (p=quarantine or p=reject), never p=none
  • The logo must be SVG Tiny Portable/Secure, not a PNG, JPG, or GIF
  • Gmail and Apple Mail require a VMC certificate proving you own the logo
At a glance
Record type DNS TXT
Hostname default._bimi.yourdomain.com
Starts with v=BIMI1
Logo format SVG Tiny P/S, min 96 x 96px
Requires DMARC enforcement + VMC
Supported by Gmail · Apple Mail · Yahoo

How BIMI works

BIMI is the visible payoff for getting authentication right. Once your domain is authenticating and enforcing DMARC, you publish a small DNS record that points to a hosted logo and (for most providers) a certificate. When a message from your domain passes DMARC, a supporting inbox fetches that logo and shows it beside the message in the message list and sometimes the open view.

It does nothing for security on its own; it is a presentation layer that only activates for mail that already authenticates. That dependency is the point: by tying the logo to a strict DMARC policy, BIMI gives brands a concrete reason to reach full enforcement, and gives recipients a visual cue that a message is genuinely from the brand it appears to be.

What BIMI requires

  • DMARC at enforcement. Your policy must be p=quarantine or p=reject with pct=100. A policy of p=none does not qualify.
  • A compliant logo. A square SVG in the strict SVG Tiny Portable/Secure profile (a tightened form of SVG Tiny 1.2), at least 96 by 96 pixels, hosted over HTTPS.
  • A BIMI DNS record. A TXT record at default._bimi.yourdomain.com pointing to the logo and, where required, the certificate.
  • A certificate. Gmail and Apple Mail require a Verified Mark Certificate (VMC), which proves you own the logo (traditionally via a registered trademark). A Common Mark Certificate (CMC) covers logos in use without a trademark, but Gmail does not display the logo for a CMC.

Anatomy of a BIMI record

The record is a single TXT entry with up to three tags: the version, the logo location, and the certificate location.

A BIMI record pointing at an SVG logo and a VMC certificate 
default._bimi.example.com.  IN  TXT  "v=BIMI1; l=https://example.com/logo.svg; a=https://example.com/vmc.pem"
  • v=BIMI1: version. Required, and must come first.
  • l=: the HTTPS URL of the SVG Tiny P/S logo. Required.
  • a=: the HTTPS URL of the VMC or CMC .pem certificate. Technically optional in the spec, but required by Gmail and Apple Mail to display the logo. Yahoo shows logos from a self-asserted record without one.

Apple Mail (iOS 16, iPadOS 16, and macOS Ventura 13 and later) and Gmail both require the VMC; a Gmail sender verified with a VMC also gets a blue checkmark next to the logo.

What it takes for a BIMI logo to appear

Your domain authenticates with SPF and DKIM
DMARC is enforcing at p=quarantine or p=reject
p=none: not eligible
You publish a BIMI record pointing to an SVG Tiny P/S logo
A VMC certificate proves you own the logo
Gmail & Apple: VMC required CMC: no logo in Gmail
A passing message shows your logo in the inbox

VMC vs CMC

VMC CMC
Full name Verified Mark Certificate Common Mark Certificate
Proves Registered trademark ownership Logo in genuine prior use
Trademark required? Yes No
Shows in Gmail? Yes (with checkmark) No
Shows in Apple Mail? Yes No

By the numbers

96x96px
The minimum logo dimensions BIMI requires; the SVG must be square and in the Tiny P/S profile.
p=reject
BIMI needs DMARC at quarantine or reject with pct=100; p=none does not qualify.
iOS 16
The Apple Mail version (with iPadOS 16 and macOS Ventura) from which BIMI logos display, given a VMC.

Common mistakes

Expecting a logo at p=none
BIMI only activates once DMARC is enforcing. A monitoring policy of p=none never qualifies, no matter how perfect the logo and record are. Reach quarantine or reject first.
Using a PNG or JPG logo
BIMI accepts only SVG in the strict Tiny Portable/Secure profile. A raster file, or even a standard SVG with disallowed elements, will not render. Convert and validate against the SVG P/S rules.
Skipping the VMC for Gmail
Gmail and Apple Mail will not show a logo from the BIMI record alone; they require a Verified Mark Certificate referenced in the a= tag. Without it you may see the logo in Yahoo but not in Gmail.
Forgetting the logo must be square
A non-square or undersized SVG fails validation. The image must be square and at least 96 by 96 pixels, with absolute pixel dimensions rather than relative units.

Frequently asked questions

Do I need a VMC for BIMI?
For Gmail and Apple Mail, yes. Both require a Verified Mark Certificate, referenced in the a= tag of your BIMI record, that proves you own the logo (traditionally through a registered trademark). Yahoo, by contrast, displays BIMI logos from a self-asserted record with no certificate at all. The certificate is optional in the raw BIMI spec, but Gmail and Apple Mail will not display a logo without one.
What are the requirements to display a BIMI logo?
Authenticate with SPF and DKIM, enforce DMARC at p=quarantine or p=reject with pct=100, host a square SVG Tiny Portable/Secure logo of at least 96 by 96 pixels over HTTPS, publish a BIMI TXT record at default._bimi.yourdomain.com, and obtain a VMC (or, for some providers, a CMC) to prove ownership of the logo.
Which email providers support BIMI?
Gmail, Apple Mail (iOS 16, iPadOS 16, and macOS Ventura or later), and Yahoo are the main inboxes that display BIMI logos, with others adding support over time. Gmail and Apple require a VMC; Yahoo was an early adopter. Support varies by client, so a logo that shows in one inbox may not appear in another.
Does BIMI improve deliverability?
Not directly. BIMI is a display feature, not a filtering signal, so it does not by itself change where mail lands. Its value is indirect: it gives you a strong reason to reach DMARC enforcement, which does help, and the visible logo can lift recognition and engagement, which feeds reputation over time.
Reviewed by Jennifer Jackson, Email Deliverability Analyst · June 2026 ← Back to glossary