What is BIMI (Brand Indicators for Message Identification)?

Definition

BIMI stands for Brand Indicators for Message Identification. It is a specification, developed through industry collaboration and described in an IETF draft, that defines how a brand can have its logo shown alongside the messages it sends. When a supporting inbox renders an email, instead of a generic placeholder or the sender's initials it can display the brand's actual logo, the same way it might show a familiar avatar.

The crucial point is that BIMI is not a standalone feature you can simply switch on. It is the visible tip of an authentication pyramid. The base is SPF, which lists your authorized sending servers. On top of that sits DKIM, which cryptographically signs your messages. Above that sits DMARC, which ties authentication to the visible From address and must be set to an enforcement policy. Only when that foundation is in place does BIMI add the logo. In other words, BIMI converts invisible authentication work into something a recipient can actually see.

BIMI also typically involves a certificate that confirms a brand legitimately owns the logo it is displaying. That prevents a bad actor from claiming a well-known brand's logo. The two certificate types, the Verified Mark Certificate and the Common Mark Certificate, differ in what they require, and the choice between them shapes how accessible BIMI is for a given organization.

How It Works

BIMI runs as a final check after authentication. When a message reaches a supporting mailbox provider, the provider first evaluates DMARC. Because BIMI requires DMARC at an enforcement policy, the provider confirms the message passes DMARC with a policy of p=quarantine or p=reject. A policy of p=none is explicitly not enough for BIMI, which is one of the most important practical facts about adopting it.

Once DMARC enforcement is satisfied, the provider looks up the BIMI record in the sending domain's DNS. That record points to the brand's logo file, which must be in a specific format: SVG Tiny Portable Secure, abbreviated SVG Tiny PS. The image has to meet strict rules, including a 1:1 square aspect ratio, a minimum size of 96 by 96 pixels, dimensions specified in absolute pixels, and a file size under roughly 32 kilobytes. Ordinary JPEG, PNG, and standard SVG files are not accepted.

The record can also reference a certificate. Where a provider requires one, such as Gmail, it validates the certificate before showing the logo. A Verified Mark Certificate proves the brand owns a registered trademark for the logo, and the submitted SVG must exactly match the trademark office image, with even small variations causing rejection. A Common Mark Certificate takes a different route: it does not need a trademark, and instead the brand demonstrates that the logo has been publicly displayed on its domain for at least twelve months. If all checks pass, the inbox renders the verified logo beside the message.

Why It Matters for Email Deliverability

It is worth being careful here, because BIMI is often misunderstood. BIMI is not a direct deliverability ranking signal. Publishing a BIMI record does not, on its own, lift your inbox placement, and a logo will not rescue a sender whose reputation is poor. Treating BIMI as a deliverability shortcut leads to disappointment.

Where BIMI genuinely helps is indirect, and the effect is real. The main benefit is the discipline it forces. BIMI cannot work without DMARC at enforcement, so any brand that adopts BIMI must move its DMARC policy to p=quarantine or p=reject. That step meaningfully protects the domain from exact-domain spoofing, because mail that fails authentication is now quarantined or rejected rather than merely monitored. Strong DMARC enforcement is genuinely good for both security and the long-term health of a sending domain.

The second benefit is recognition and trust. A verified logo next to a message helps recipients identify legitimate mail at a glance and is harder for impersonators to fake. That can support higher open and engagement rates, and engagement is one of the signals mailbox providers use to decide placement. So the chain runs from BIMI to DMARC enforcement and brand recognition, then from those to engagement and reputation, and finally to deliverability. BIMI matters, but it matters because of what it requires and what it signals, not as a lever you pull on its own.

How VeriMails Handles It

VeriMails does not issue BIMI certificates and does not host BIMI logos; those come from certificate authorities and your DNS configuration. What VeriMails does is support the foundations BIMI depends on and the recipient-side hygiene that keeps a logo-bearing campaign performing well.

BIMI rests on the SPF, DKIM, and DMARC stack, and VeriMails offers free tools for each layer: an SPF generator, a DKIM generator, and a DMARC generator. These help you create correct DNS records, which is the necessary groundwork before BIMI is even possible, since BIMI requires DMARC published at an enforcement policy. Getting that authentication foundation right is the first practical step toward a BIMI logo.

The other half is your list. A BIMI logo gives a campaign a polished, trustworthy appearance, but that appearance is undermined if the campaign is sent to a list full of invalid addresses, because the resulting bounces and complaints damage the sender reputation that decides whether your authenticated, logo-bearing mail reaches the inbox at all. VeriMails verifies your recipient list through a full multi-layer process: syntax validation, MX and DNS confirmation, a live SMTP handshake with the receiving mail server, and detection of catch-all domains, disposable addresses, and role-based addresses. You can verify a list as a CSV upload or check addresses individually through the REST API, with clear deliverability categories. New accounts get 100 free credits on signup with no credit card required and credits that never expire, with verification from 0.0019 dollars per email, which is 19 dollars for 10,000 credits, and subscriptions from 15 dollars per month. Strong authentication earns the logo; a clean, verified list keeps the campaign behind it landing in the inbox.

Frequently Asked Questions