What is BIMI and How to Set It Up

• Increases brand trust: Recipients see your official logo next to your emails.

• Improves recognition: Your emails stand out in crowded inboxes.

• Encourages stronger security: BIMI requires DMARC enforcement, which helps prevent spoofing and phishing.

Prerequisites (Required for All BIMI Setups)

Before BIMI can work, your sending domain must meet these requirements:

1. Confirm Your Sending Domain

BIMI applies to the domain used in your visible From address.

For example:

• news.example.com and example.com are treated as different domains.

• The domain used in the From address must have SPF, DKIM, DMARC, and BIMI configured.

2. SPF and DKIM Must Be Configured

Your domain must successfully authenticate with SPF and/or DKIM so that DMARC can pass with alignment.

BIMI relies on DMARC passing — if DMARC fails, BIMI will not display.

3. DMARC Must Be Enforced

Monitoring-only DMARC (p=none) is not sufficient for BIMI.

Minimum requirement:

• p=quarantine or p=reject

For Gmail specifically:

• pct=100 is required

Example DMARC record:

Provider-Specific Requirements

Gmail (Most Strict)

To display a BIMI logo in Gmail, you must have:

• DMARC enforced (p=quarantine or p=reject) with pct=100

• A VMC (Verified Mark Certificate) or CMC (Common Mark Certificate)

• A BIMI DNS record pointing to your certificate (PEM file)

Gmail’s verified checkmark experience is tied to VMC/CMC certification.

Yahoo / AOL

• May display BIMI using a self-asserted logo (no certificate required)

• SPF, DKIM, and enforced DMARC are still required

• VMC/CMC can be used if available

Apple Mail / iCloud

• BIMI support varies by mailbox behavior

• Strong authentication and certification improve the likelihood of display

Microsoft (Outlook / Hotmail / Exchange Online)

• BIMI logos are not reliably supported

• SPF, DKIM, and DMARC are still strongly recommended for deliverability and security

How to Set Up BIMI (Gmail-Ready)

Step 1 — Prepare Your BIMI Logo

• Must be SVG Tiny PS (tiny-ps), not a standard SVG

• Host the file publicly over HTTPS

Example:

Step 2 — Obtain a VMC or CMC (Required for Gmail)

• VMC: Requires a trademarked logo

• CMC: Available for some non-trademark scenarios

The certificate is provided as a PEM file.

Example: https://images.example.com/bimi/certificate.pem

Step 3 — Host Files Over HTTPS

Ensure that:

• URLs are publicly accessible

• No authentication is required

• HTTPS is valid and stable

• Files are not frequently changed

Step 4 — Publish the BIMI DNS Record

BIMI record location:

• DNS propagation and provider verification can take up to 48 hours

• Mailbox providers cache results, so updates are not always immediate

Troubleshooting: Why Logos Don’t Appear

Common reasons BIMI logos fail to display:

• DMARC is not enforced (p=none)

• Gmail-specific: pct is not set to 100

• BIMI record published on the wrong domain (root vs subdomain mismatch)

• SVG is not truly BIMI-compliant (tiny-ps)

• Missing or invalid VMC/CMC for Gmail

• HTTPS hosting issues (blocked access, redirects, TLS errors)

Need Help?

If you have questions or need assistance, please contact our support team at support@tryletterhead.com or log a support ticket through the Help Center!