What is BIMI and its Role in Email Authentication & Security

The Email Security Crisis: Why BIMI Matters

Cybercriminals no longer need to hack systems; they just need to look legitimate. A stolen logo. A familiar sender name. A forged domain. It’s all it takes to slip past defenses and into the inbox of an employee, a customer, or a partner. From there, the damage spreads – phishing scams, business email compromise (BEC), leaked data, and lost trust.

Brand Indicators for Message Identification, or BIMI, changes that equation. It brings verified visual identity into the authentication process, giving your domain a recognizable face, backed by security protocols like DMARC, SPF, and DKIM.

BIMI is email security meeting brand trust. And it’s long overdue.

In this blog, we’ll break down how BIMI works, what it takes to implement it, and why it matters for IT teams, marketers, and brand owners alike.

What is BIMI (Brand Indicators for Message Identification)?

BIMI is a DNS-based email specification that allows display of a brand logo in the recipient’s inbox, only after passing strict authentication checks. Developed by the AuthIndicators Working Group, which includes industry leaders like Google, Verizon Media, Fastmail, and Proofpoint – BIMI was introduced to bring visual trust to authenticated emails and reduce brand spoofing.

It is not a standalone security protocol, but a visual layer that builds on top of DMARC, SPF, and DKIM. BIMI makes sure that only emails that pass domain-level authentication can present an organization’s logo, adding a layer of brand integrity and trust to every message.

For senders, it’s a rare opportunity to merge authentication with branding at protocol level. For recipients, BIMI makes it instantly clear who the sender is. It aligns security with recognition (logo + domain alignment), so your audience knows your emails are real the moment they land.

Rather than relying on email content or headers to build trust, BIMI pulls from verified DNS records and cryptographic validations to determine whether a sender is authorized to display a specific logo. This helps recipients instantly recognize legitimate messages, while holding senders more accountable across the global email ecosystem.

What Your Emails Look Like – With and Without BIMI

Here’s what your recipients see.

With BIMI, your logo shows up next to your name. Without it, you’re just another message.

How BIMI Works with Email Authentication Protocols?

BIMI operates only when a domain has implemented and enforced the foundational email authentication protocols:

• SPF (Sender Policy Framework)

  Validates whether the sending mail server is authorized to send on behalf of the domain. It uses DNS to define allowed IP addresses.

• DKIM (DomainKeys Identified Mail)

  Applies a cryptographic signature to outbound emails, enabling recipients to verify message integrity and confirm the domain’s involvement in transmission.

• DMARC (Domain-based Message Authentication, Reporting & Conformance)

  Combines the results of SPF and DKIM. It enforces domain alignment and provides instructions to receivers on how to handle failed authentication. BIMI requires the domain to have a DMARC policy of quarantine or reject.

BIMI acts only after these protocols succeed. It introduces a DNS TXT record that points to a verified brand logo and, optionally, a Verified Mark Certificate (VMC).

What You Need to Implement BIMI?

To qualify for BIMI logo rendering, the following technical conditions must be met:

• A DMARC record must be configured with a policy of p=quarantine or p=reject. Policies set to none are not eligible for BIMI.
• The domain in the “From” header must align with identifiers authenticated via SPF and/or DKIM to meet DMARC alignment.
• The brand logo must be in SVG Tiny Portable/Secure (Tiny PS) format. The file must adhere to BIMI’s security specifications – no scripts, external links, or animations and must be hosted over HTTPS.
• A published BIMI DNS TXT record at default._bimi.domain.com, declaring the logo’s URL (and VMC certificate if applicable).

Any failure in DNS setup, authentication alignment, or logo compliance will prevent the logo from being displayed in supported mailbox providers.

Example: BIMI DNS Record Structure

To enable BIMI, your domain must publish a DNS TXT record under a specific selector. This record links your domain to your verified logo and optionally, your Verified Mark Certificate.

default._bimi.example.com. IN TXT "v=BIMI1;
l=https://bimi.example.com/logo.svg;
a=https://bimi.example.com/vmc.pem"

Breakdown:

• default._bimi.example.com The standard DNS selector used for BIMI.
• IN TXT Indicates this is a TXT-type DNS record.
• v=BIMI1 Specifies the version of BIMI being used.
• l= Points to the logo in SVG Tiny PS format, hosted over HTTPS.
• a= (Optional) Specifies the location of the Verified Mark Certificate (required for Gmail and Apple Mail).

If the BIMI record is missing, malformed, or linked to failed authentication (SPF, DKIM, or DMARC), the logo will not be displayed, even if a VMC is present.

The Role of VMC Certificate in Enabling BIMI Logo Display

While BIMI relies on domain-level authentication, inboxes like Gmail and Apple Mail require a higher standard of trust before displaying a brand logo. To fully activate BIMI in these platforms, a Verified Mark Certificate is required.

A VMC is a digital certificate that validates the ownership of a legally registered trademarked logo for use in BIMI-compliant email communications. This additional layer of validation allows mailbox providers to safely render logos at scale, without the risk of impersonation or brand misuse.

In essence, VMC certificate ensures that logo display isn’t just based on technical authentication, but also on verified legal ownership. It completes the trust chain required by major mailbox providers enforcing stricter brand display policies.

Visual identity influences open rates and sender credibility, and VMC gives your domain a verified presence that stands out from generic senders.

BIMI-Compatible Email Platforms and Display Behavior

BIMI adoption is steadily growing across major mailbox providers. While the core requirement is BIMI compliance (SPF, DKIM, DMARC, and a published logo), how and when a logo is displayed varies by platform, especially when a Verified Mark Certificate is required.

Here’s how key email platforms currently support BIMI:

As the ecosystem matures, more clients are expected to support BIMI either natively or through plugin-based integrations. Maintaining strong domain authentication remains essential for future-proof compatibility.

As of April 2025, the following mailbox providers support BIMI (Brand Indicators for Message Identification):

BIMI Certificate Cost Breakdown and ROI Justification

Setting up a BIMI certificate involves aligning email authentication protocols with visual branding, but the commercial impact makes it well worth the investment.

What Does a BIMI Certificate Cost?

While publishing a BIMI record is free, achieving full display functionality with your BIMI and VMC implementation, comes with setup requirements:

SSL2BUY offers complete support for DMARC enforcement, BIMI certificate setup, and affordable digital certificates to help businesses achieve inbox logo display. Our valued customers get:

• Free DMARC setup assistance
• Help with SVG formatting and compliance
• Access to low-cost DigiCert Verified Mark Certificates

Why It’s Worth It?

• Your emails look like they belong – not like just another marketing blast or risky unknown sender.
• People trust what they recognize. A verified logo builds familiarity before the email is even opened.
• You spend time crafting emails – BIMI helps them get seen.
• It stops attackers from stealing your brand’s identity – visually and technically.
• The cost is small compared to the trust you gain. Or the trust you could lose without it.

One phishing attack can cost thousands. A properly configured BIMI certificate setup protects your domain and amplifies your brand presence at a fraction of that risk.

Final Thoughts – Branding and Security in One Move

BIMI turns email authentication into something your customers can actually see.

It reinforces domain security while giving your brand a verified presence in the inbox, which is visible, consistent, and trusted. When supported by DMARC and a Verified Mark Certificate, BIMI not only protects against impersonation but strengthens every email your business sends.

Ready to Implement BIMI? We Can Help

If your domain is secure, your logo should prove it. Check your readiness and make BIMI part of your email strategy. SSL2BUY makes it easy to implement your BIMI certificate setup – explore our solutions and start today!

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