What BIMI actually does
You've probably noticed that some company emails in Gmail show a brand logo next to the sender name instead of the generic coloured initial. That's BIMI in action.
When a receiving mail server sees your email, it checks for a BIMI DNS record. If one exists and your domain meets the requirements, your logo is fetched and displayed in the inbox. Recipients see your logo before they even open the email.
Which email clients support BIMI?
BIMI is supported (or being rolled out) in:
- Gmail — fully supported, including on mobile
- Yahoo Mail and AOL — fully supported
- Apple Mail — rolling out
- Fastmail — supported
Microsoft Outlook does not currently support BIMI — it uses its own system called BIMI for Microsoft 365. Outlook's market share means BIMI won't reach all your recipients, but for Gmail and Yahoo users (the majority of consumer inboxes) it works well.
What you need to set up BIMI
BIMI has strict requirements:
1. A strong DMARC policy
Your domain must have DMARC set to p=quarantine or p=reject. A p=none policy won't qualify. This ensures BIMI logos only appear on properly authenticated email.
2. An SVG logo file
Your logo must be in a specific SVG format called SVG Tiny PS — a stripped-down version of SVG that's consistent across renderers. It must be square, hosted at a public HTTPS URL, and typically under 32KB. Most design tools can export SVG Tiny PS, or you can use a conversion tool.
3. A BIMI DNS record
Add a TXT record at default._bimi.yourdomain.com:
v=BIMI1; l=https://yourdomain.com/logo.svg4. (Optional but recommended) A VMC certificate
A Verified Mark Certificate (VMC) is a paid certificate from a certificate authority (Entrust or DigiCert) that cryptographically verifies your logo is associated with your brand. Gmail requires a VMC to show the logo with a blue checkmark (the "verified sender" badge). Without a VMC, some providers won't show the logo at all.
VMCs cost around $1,000–$1,500 per year and require a registered trademark.
Is BIMI worth setting up?
For large brands sending significant email volume, yes — the logo increases brand recognition and open rates, and the VMC requirement acts as a trust signal. For smaller businesses, the VMC cost and trademark requirement make it a lower priority.
You can still add the BIMI DNS record with just an SVG (no VMC) — some providers will show it, and you're set up for when VMC support becomes more widely accessible.
Why BIMI matters for security
Because BIMI requires strong DMARC enforcement, it creates a meaningful trust signal. When recipients see your logo in Gmail, it means the email was authenticated — spammers impersonating your domain can't show your logo because they can't pass DMARC. This makes your branded email meaningfully harder to phish with.