Is BIMI easily spoofed and are there drawbacks to BIMI implementation?
Michael Ko
Co-founder & CEO, Suped
Published 29 Jun 2025
Updated 16 Aug 2025
9 min read
When Brand Indicators for Message Identification (BIMI) first emerged, a common question was whether it could be easily spoofed. The idea of displaying a verified brand logo directly in the inbox is powerful for building trust, but naturally, concerns arose about its security. After all, if a bad actor could easily display a false logo, BIMI would do more harm than good.
My experience in email security suggests that while no system is entirely foolproof, BIMI is designed with significant safeguards. Its architecture, heavily reliant on established email authentication protocols and a robust verification process for logos, makes it far from easily spoofed. However, like any advanced email standard, it does come with certain implementation complexities and potential drawbacks.
Understanding how BIMI works and its foundational requirements is key to addressing these concerns. It's not just about adding a logo, it's about validating your brand's legitimacy through a layered security approach.
At its core, BIMI’s ability to display a logo is contingent on a strong foundation of email authentication. Specifically, it requires a DMARC (Domain-based Message Authentication, Reporting, and Conformance) policy set to quarantine or reject. This is not a suggestion, it is a strict requirement by most mailbox providers for a BIMI logo to even appear. This means that before a logo is shown, the email must pass DMARC checks, which themselves rely on SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) authentication.
DMARC’s enforcement policy ensures that if an email claiming to be from your domain fails its SPF or DKIM checks, it will either be moved to spam (quarantine) or outright blocked (reject). This is the primary mechanism that makes spoofing difficult, as it directly addresses the unauthorized use of your domain in the From: address. If a malicious sender tries to spoof your domain, their email will likely fail DMARC authentication, preventing their message, and certainly any associated BIMI logo, from reaching the recipient's inbox successfully.
Therefore, BIMI itself doesn't directly prevent spoofing. Instead, it leverages the anti-spoofing capabilities of DMARC. This synergistic relationship means that if your DMARC is properly configured and enforced, your domain is already well-protected against impersonation, and BIMI adds a visual layer of trust to those authenticated emails. You can find more information about BIMI's role with DMARC from Mailgun's blog.
The role of Verified Mark Certificates in preventing spoofing
Another crucial layer in BIMI's security framework, particularly for major mailbox providers like Gmail and Apple Mail, is the Verified Mark Certificate (VMC). A VMC is a digital certificate issued by a Certificate Authority (CA) that cryptographically verifies the authenticity of your brand logo and its association with your domain. This certificate is linked to a registered trademark, which undergoes a rigorous validation process by the CA.
The concern that bad actors could easily obtain a VMC for a similar-looking logo is largely unfounded due to the stringent requirements set by CAs. They perform extensive checks to ensure that the applicant genuinely owns the trademark for the logo they wish to display. This process is time-consuming and expensive, acting as a significant barrier for would-be spoofers.
While a VMC isn't strictly necessary for all BIMI implementations, particularly for some smaller mailbox providers, it is becoming increasingly standard for widespread adoption and for the logo to appear in prominent email clients. The high cost and complexity involved in obtaining a legitimate VMC make it an unattractive and impractical avenue for typical phishing operations that rely on low-cost, high-volume tactics and cycling through domains.
The official BIMI Group FAQs provide more details on the role of VMCs.
Drawbacks of BIMI implementation
Despite its security benefits, BIMI implementation does come with certain drawbacks and challenges. These are less about BIMI being easily spoofed and more about the resources, knowledge, and ongoing effort required.
Trademark requirement
A significant hurdle for many organizations is the requirement for a registered trademark of the logo. Without a valid, globally recognized trademark, you cannot obtain a VMC, which severely limits your BIMI visibility in key inboxes. Obtaining a trademark can be a lengthy and costly process, especially for newer or smaller brands.
Cost of VMC
Verified Mark Certificates are not free. They involve annual or multi-year subscription fees to Certificate Authorities. For organizations managing multiple domains or subdomains, these costs can add up. This financial commitment is often cited as a reason for slow BIMI adoption.
Technical complexity
Implementing BIMI requires a solid understanding of DNS records, DMARC, and specific SVG image formatting. Misconfigurations can lead to the logo not displaying or, worse, impacting email deliverability if DMARC alignment is inadvertently broken. Proper setup involves:
DMARC Enforcement: Ensuring your DMARC policy is at p=quarantine or p=reject. This is a non-negotiable prerequisite.
SVG Logo Formatting: Your logo must be in a specific SVG Tiny PS format, which often requires professional graphic design or conversion tools.
DNS Record Publication: Creating and publishing a TXT record in your DNS with the BIMI information, including the link to your VMC if used.
These technical requirements can be a stumbling block for organizations without dedicated IT or email deliverability teams. You can learn more about BIMI implementation steps in detail.
Benefits of BIMI
Despite the implementation challenges, the benefits of BIMI often outweigh the drawbacks, especially for brands serious about their email presence and security posture.
Enhanced brand recognition and trust
The most visible benefit is the immediate brand recognition in the inbox. Seeing a familiar logo next to the sender's name helps recipients quickly identify legitimate emails, fostering trust and improving the user experience. This visual cue can lead to higher engagement and open rates.
Improved anti-phishing defense
While BIMI doesn't directly prevent spoofing, it acts as a strong deterrent. By visually distinguishing authenticated emails, it trains recipients to expect and look for your logo. The absence of your logo on a suspicious email, even if it tries to spoof your domain, becomes a clear red flag for the recipient, helping them to avoid phishing attempts. This visual trust layer complements your existing DMARC security.
Demonstrates commitment to email security
Implementing BIMI signals to mailbox providers and recipients that your brand is committed to email security and best practices. This can positively influence your domain reputation and potentially enhance email deliverability over time. A table illustrating the trade-offs might be helpful:
Misconception: Some mistakenly believe that malicious actors can easily obtain a Google blue checkmark or a Verified Mark Certificate (VMC) for a nearly identical logo from a foreign country's trademark office. This suggests a perceived loophole in the authentication process where CAs might overlook similarities.
Reality: The certification process for VMCs is robust, requiring clear ownership of a trademarked logo. CAs have stringent validation procedures in place to prevent such exploits, making it an expensive and difficult undertaking for bad actors. Furthermore, mailbox providers maintain the ultimate discretion on whether to display a logo, even if a valid VMC exists.
The core security of BIMI lies in its integration with DMARC. Without a DMARC policy enforced at quarantine or reject, BIMI simply won't function as intended, and your domain remains vulnerable to direct spoofing (or phishing via an exact domain impersonation) regardless of any BIMI setup. The logo serves as a visual indicator of that underlying DMARC security.
In essence, BIMI amplifies the security and trust established by your existing email authentication protocols. It's a brand-building tool that relies on a strong security foundation, rather than a standalone security solution.
Views from the trenches
Best practices
Ensure your DMARC policy is set to p=quarantine or p=reject for the domains you intend to implement BIMI on. This is non-negotiable for logo display.
Obtain a Verified Mark Certificate (VMC) for your trademarked logo from an accredited Certificate Authority to ensure maximum visibility across supporting mailbox providers.
Properly format your logo as an SVG Tiny PS file and host it on a secure HTTPS server for the BIMI record.
Monitor your DMARC reports regularly to ensure that your legitimate emails are passing authentication before implementing BIMI, preventing deliverability issues.
Common pitfalls
Attempting BIMI implementation without a DMARC policy at enforcement, leading to the logo not displaying.
Using a logo that isn't trademarked or failing to obtain a VMC, limiting BIMI's effectiveness on major platforms.
Incorrect SVG formatting or hosting the SVG file on an insecure HTTP server, preventing the logo from rendering.
Overlooking ongoing monitoring of BIMI and DMARC records, which can lead to display issues or security vulnerabilities if not maintained.
Expert tips
Consider a phased rollout for BIMI, starting with monitoring DMARC reports at p=none to identify all legitimate sending sources before moving to enforcement and then BIMI.
Regularly check your BIMI DNS record and VMC expiration dates to avoid unexpected logo disappearance.
If your logo changes, remember to update your VMC and BIMI DNS record accordingly, as this is a common oversight.
Consult with an email deliverability expert or a BIMI specialist if you encounter complex issues or need assistance with advanced configurations.
Marketer view
Marketer from Email Geeks says they asked a network vendor who suggested BIMI was a bad idea because it could be easily spoofed via existing cert authorities.
2022-04-08 - Email Geeks
Expert view
Expert from Email Geeks says that such spoofing is nearly impossible because the checks performed by Certificate Authorities are very thorough.
2022-04-08 - Email Geeks
Is BIMI worth the effort?
BIMI is not easily spoofed when implemented correctly. Its robustness stems from its reliance on enforced DMARC policies and, for full effect, the rigorous verification process of a Verified Mark Certificate. These underlying mechanisms create a strong defense against impersonation.
The primary drawbacks of BIMI are not security vulnerabilities, but rather the investment required in terms of cost (for trademarks and VMCs) and technical effort to ensure proper setup and ongoing maintenance. However, for brands aiming to enhance their email presence, build trust with recipients, and reinforce their commitment to email security, the benefits of BIMI are substantial.
Ultimately, BIMI is a valuable addition to a comprehensive email security and deliverability strategy. It serves as a visual trust signal that complements, but does not replace, the essential authentication protocols that protect your domain from spoofing and phishing attacks.
Gmail and 
Apple Mail, is the Verified Mark Certificate (VMC). A VMC is a digital certificate issued by a Certificate Authority (CA) that cryptographically verifies the authenticity of your brand logo and its association with your domain. This certificate is linked to a registered trademark, which undergoes a rigorous validation process by the CA.
Google blue checkmark or a Verified Mark Certificate (VMC) for a nearly identical logo from a foreign country's trademark office. This suggests a perceived loophole in the authentication process where CAs might overlook similarities.
