BIMI lets mailbox providers display your brand logo next to authenticated emails. It builds on DMARC and helps recipients visually trust messages from your domain.
How BIMI Works
- Authentication first: Your messages must pass DMARC with alignment (SPF or DKIM) and use an enforcement policy (p=quarantine or p=reject).
- BIMI record: Publish a DNS TXT at default._bimi.example.com pointing to your logo and optional VMC.
- Mailbox provider checks: If DMARC passes and policy is enforced, the provider fetches your logo and (for some providers) validates your VMC.
DNS Record Format
Publish a TXT record at default._bimi.example.com with at least a logo URL (l=). Add a VMC URL (a=) where required:
💡 Quick Start: Generate a valid BIMI record instantly with our free builder tool.
Free BIMI Record Generator- v: Protocol version (BIMI1).
- l: HTTPS URL to an SVG logo meeting BIMI constraints.
- a: HTTPS URL to a Verified Mark Certificate (VMC) in PEM (required by Gmail; optional for some other providers).
Logo Requirements (SVG)
- SVG Tiny P/S (profile used by BIMI); no scripts, no external references, no animation.
- Square aspect, centered artwork with safe margins; background filled (not transparent) to ensure contrast in dark themes.
- Single logo, no text-only marks preferred; keep file size modest (e.g., < 32KB where practical).
- Serve over HTTPS with a stable URL; set long cache headers.
VMC (Verified Mark Certificate)
A VMC is an X.509 certificate from an authorized CA (e.g., Entrust, DigiCert) that asserts your right to use the logo. Gmail requires a valid VMC; Yahoo may display logos without a VMC, but policies vary by provider.
Selectors (Advanced)
By default providers query default._bimi.example.com. You can publish additional selectors and reference them from messages using the BIMI-Selector header:
Deployment Checklist
- Ensure DMARC at enforcement (p=quarantine or reject) and messages pass DMARC with alignment.
- Host BIMI‑compliant SVG logo at a stable HTTPS URL; acquire a VMC if required by your target providers.
- Publish the BIMI TXT at default._bimi.example.com with v=BIMI1, l= logo URL, and optional a= VMC URL. → Use our free BIMI generator
- Send test emails to seed accounts on Gmail/Yahoo and verify logo display after provider caches update.
Validation & Troubleshooting
- Check DNS: dig TXT default._bimi.example.com +short
- Fetch logo: curl -I https://brand.example.com/bimi/logo.svg (must be HTTPS, correct content‑type)
- Confirm DMARC: Policy must be enforced and pass alignment for your traffic.
Common issues: DMARC not enforced, SVG contains disallowed features, mismatched brand/legal entity vs VMC, or incorrect TXT formatting (missing semicolons).