BIMI Email Authentication: Setup, Strategy, and Impact

BIMI (Brand Indicators for Message Identification) is an email standard that enables organisations to display their official logo next to authenticated emails in supporting inboxes. It acts like a “verified badge” for email, instantly conveying brand recognition and trust. When recipients see a familiar logo beside the sender name, they can quickly identify legitimate messages and distinguish them from generic or spoofed emails.

In crowded inboxes, this visual cue catches the eye and signals that the message is genuine. By reinforcing brand identity, BIMI both improves engagement rates and helps combat phishing: seeing the official logo builds confidence that the mail is truly from the brand's domain.

Technical Prerequisites

To implement BIMI, strict email authentication must already be in place. Your domain needs valid SPF and DKIM records authorising all legitimate senders, and a DMARC policy set to enforcement. The BIMI standard requires aligned SPF and DKIM (so the From: domain matches the signing domain) and a DMARC policy of p=quarantine or p=reject (at 100% of messages) on the organisational domain and subdomains.

“None” or partial pct<100 DMARC policies will not qualify for BIMI.

In practice, this means configuring SPF to list your mail servers, DKIM to cryptographically sign outgoing mail, and publishing a strict DMARC TXT record (for example: v=DMARC1; p=reject; pct=100; ...). Without these prerequisites, BIMI will not function. It's important to understand that the very purpose of BIMI is to build on the strongest authentication setup.

Step-by-Step Setup

The BIMI implementation involves several key steps:

Authenticate email and enforce DMARC. Ensure all mail streams (marketing, transactional, etc.) use valid SPF and DKIM that align with your sending domain, and set DMARC to quarantine or reject with 100% enforcement. The BIMI Group explicitly states “DMARC policy MUST be at enforcement (quarantine or reject)” and that any “None” policy will not be accepted.

This provides the security foundation for BIMI.

Create a BIMI-compliant logo in SVG format. Produce a Scalable Vector Graphics (SVG) version of your official logo, following the Tiny PS (Presentation) profile. The SVG should be square (1:1 aspect ratio) and render cleanly on both light and dark backgrounds. (Mail clients will scale this up or down as needed.)

Make sure the logo is trademarked or owned by your organisation and that you have a logo certificate (VMC or CMC). Although optional for some providers, major inboxes (notably Gmail and Apple Mail) require a Verified Mark Certificate (VMC) to display a BIMI logo.

A VMC is a certificate issued by an approved Certificate Authority (e.g. DigiCert or Entrust) after verifying your organisation’s identity and trademark rights to the logo.

If your logo isn’t trademarked, a Common Mark Certificate (CMC) may be used, but it has different restrictions. The CA will validate your trademark registration and organisational details before issuing the certificate, usually in PEM format.

Publish the BIMI DNS record. Add a TXT record under default._bimi.yourdomain.com that points to your logo (and certificate).

For example:

default._bimi.yourdomain.comINTXT"v=BIMI1; l=https://yourdomain.com/logo.svg; a=https://certificateissuer.com/vmc.pem"

Here, the l= tag holds the HTTPS URL of your SVG logo, and the a= tag (optional) holds the URL of your VMC/CMC file.

Once the record is live, mailbox providers can fetch it to verify your logo and certificate. BIMI Group provides tools (such as the BIMI Inspector) to check record syntax and validity.

Platform-Specific Requirements (e.g. Google Workspace, Apple Mail)

Different email platforms have their own BIMI requirements:

Google Workspace (Gmail). Gmail now mandates a Verified Mark Certificate (VMC) for BIMI. To be eligible, the sending domain must have a strict DMARC policy (p=quarantine or reject, pct=100%) and a Google-approved VMC for the logo.

Once implemented, Gmail will display a blue checkmark next to messages from verified senders.

The Google Admin documentation stresses that third-party certification (VMC/CMC) is required, and that the server hosting the BIMI logo must use HTTPS with strong TLS.

Apple Mail apps support BIMI on recent operating systems. Apple requires that the sending domain be on BIMI’s list of supported providers and that the mail comply with DMARC and BIMI specifications.

Crucially, Apple also expects a Verified Mark Certificate (or other trusted “BIMI evidence document”) to validate the logo’s authenticity.

In other words, Apple will only display the logo if the sender’s domain passes DMARC checks and the logo is verifiably owned by the organisation.

Yahoo does not currently require a VMC for BIMI. In practice, domains with a BIMI record can see logos in Yahoo inboxes even without a certificate. However, if a VMC is included in the record, Yahoo will use it (sometimes showing a purple check mark) to signal verification.

Aside from the above, other mail providers may have varying levels of BIMI support. Many require at least DMARC enforcement.

Some, like Microsoft’s Outlook/Office 365, have limited or no BIMI support at present. Note also that individual providers retain discretion: they may only display logos for senders with good sending reputations and sufficient volume.

Strategic Benefits for Brand Visibility and Email Trust

For technical marketing professionals, BIMI offers clear strategic advantages:

Enhanced brand visibility in the inbox. Every email becomes an opportunity to reinforce brand identity. A recognisable logo next to the sender name immediately catches the recipient’s eye and distinguishes the message from others.

This “eye-catching” effect boosts engagement: studies have found significant open-rate lifts when logos are present.

And over time, consistent logo exposure helps recipients associate your visual identity with your brand, improving recall and trust.
Trust-building and phishing protection. A BIMI logo acts as a visual stamp of authenticity. Recipients intuitively trust emails displaying an official logo. While they might not know this means the sender has passed DMARC checks, they intuit that there is a trust layer that has been built in.

This helps combat phishing: fraudulent senders cannot get their logo displayed unless they control the domain and pass authentication. Thus, BIMI reduces the risk of customers being duped by imposter emails.

But the important takeaway is that branded inbox logos foster consumer confidence, as users associate the logo with a legitimate brand presence.
Search and SEO alignment. While BIMI is an email standard, it ties into broader digital trust signals. A domain with strict DMARC and visible brand logos demonstrates a commitment to security and authenticity – qualities that align with modern SEO and branding best practices.

In an era where Google’s algorithms increasingly value user trust and brand authority, having a verified sender reputation can be seen as complementary to your overall online presence.

Furthermore, higher email engagement (opens, clicks) driven by BIMI can lead to increased traffic and conversions, indirectly benefiting search performance and brand metrics.
A competitive advantage. As of 2025, BIMI adoption remains relatively low (around 5-10% of domains). Brands that implement it gain an edge by standing out more in inboxes and signalling professionalism.

Early adopters report not only higher opens but also stronger customer loyalty, as a visible logo reassures subscribers they are dealing with a trusted sender.

Conclusion

In summary, BIMI enables marketers to extend their brand’s visual identity directly into the inbox, building recognition and trust at a glance. It creates an immediate signal of legitimacy that can boost campaign performance and support the brand’s security narrative.

BIMI’s security impact comes mainly from its authentication requirements. By enforcing SPF, DKIM, and strict DMARC, BIMI makes it much harder for attackers to spoof your domain or sender identity. This helps protect recipients from phishing and preserves your brand reputation.

Moreover, because only properly authenticated mail can carry your logo, BIMI helps ensure that customers see your brand banner only on legitimate communications. In terms of deliverability, BIMI itself doesn’t magically send more mail to the inbox. However, its prerequisites strengthen deliverability indirectly.

A domain with enforced DMARC and aligned SPF/DKIM is inherently more trustworthy to mailbox providers. Sending BIMI-signed emails sends a strong signal to email systems that you are a legitimate sender.

Providers are less likely to mark such mail as spam. In addition, higher engagement metrics from BIMI-enhanced emails (opens, clicks) further signal to ISPs that recipients want your mail.
Conversely, if your BIMI setup is misconfigured (e.g. bad DMARC), you risk delivery failures, so careful implementation is critical. Mailbox providers still apply their own spam filtering and reputation criteria. Even with BIMI, if you have poor sending practices or low reputation, logos may not appear.

The truth is that a mailbox provider’s decision to show a BIMI logo “is still contingent upon the mailbox provider’s discretion” based on factors like sender reputation and volume.
Therefore, BIMI should be part of a holistic email strategy: maintain list hygiene, avoid spam traps, and monitor your domain’s DMARC reports. Finally, there are costs and operational considerations. Obtaining a VMC involves a vetting process and annual fee (around $1,500/year).
Managing the SVG logo and DNS record can require coordination between marketing and IT teams. Yet these investments yield security benefits: they discourage brand impersonation and reinforce consumer trust. In practice, many organisations find that the deliverability advantages of a strict DMARC policy and the marketing lift from branded logos justify the effort.