This guide assumes BIMI is already deployed and passing. It covers what breaks at scale and how mature teams operate it.
Edge cases that break a working setup#
- Publishing BIMI while DMARC is still at p=none; providers ignore the record.
- Uploading a standard SVG exported from a design tool; it must be the Tiny PS profile with no scripts or external references.
- Hosting the logo on a non-HTTPS URL or behind a redirect.
- Mail forwarded through mailing lists or personal forwarders, which alters headers and content.
- Acquisitions and rebrands that introduce domains nobody audited.
- Vendors silently changing their sending infrastructure.
Operating it as infrastructure#
- Assign an owner for each sending domain and each vendor relationship.
- Put DNS records under version control or a change-review process.
- Alert on authentication pass rate drops and reputation changes, not just outages.
- Run a quarterly audit against the setup steps below.
- Document runbooks for the three most common failures.
Reference: the baseline setup#
- Reach DMARC p=quarantine (pct=100) or p=reject on the sending domain.
- Produce your logo as an SVG Tiny 1.2 Portable/Secure file, square, centered, with a solid background.
- Obtain a VMC or CMC from an approved certificate authority if you want display in Gmail and Apple Mail.
- Publish default._bimi.yourdomain.com with l= (logo URL) and a= (certificate URL).
- Validate with a BIMI inspector and send a test to Gmail, Yahoo, and Apple seed accounts.
default._bimi.example.com. IN TXT "v=BIMI1; l=https://example.com/brand/logo.svg; a=https://example.com/brand/vmc.pem"Frequently asked questions#
Does BIMI work without a VMC?
Yahoo and Fastmail display BIMI logos with DMARC enforcement alone. Gmail and Apple require a VMC or CMC.
What image format does BIMI require?
SVG Tiny 1.2 Portable/Secure. No PNG, JPG, or standard SVG.
Does BIMI improve deliverability?
Not directly. Its prerequisite, DMARC enforcement, does. The logo mainly lifts engagement and trust.