What is the cause of the unexpected banner appearing in Gmail desktop and is it resolved?
Michael Ko
Co-founder & CEO, Suped
Published 15 May 2025
Updated 19 Aug 2025
7 min read
Email is a cornerstone of digital communication, and when something unexpected pops up, it can be quite alarming. Recently, some Gmail desktop users reported seeing an unusual banner appear across all their incoming emails. This wasn't a typical spam warning or a notification about a new feature, but a persistent, unexpected message that raised questions about email security and deliverability.
When such banners appear, especially affecting a wide range of emails from various senders, it naturally leads to concerns. Senders might worry if their legitimate messages are being flagged incorrectly, impacting their ability to reach recipients. Recipients, on the other hand, might become wary of opening emails, even from trusted sources, if a warning banner suggests a problem.
Understanding the root cause of these anomalies is crucial for maintaining trust and ensuring smooth email flow. This kind of event underscores the delicate balance in email ecosystems, where even minor glitches can have significant implications for both senders and recipients.
What was the unexpected banner?
The unexpected banner that appeared in Gmail desktop was a specific warning message displayed prominently above the email content. Users reported that it affected all types of emails, including transactional emails, newsletters, triggered messages, and general marketing communications. This broad impact suggested a systemic issue rather than a sender-specific problem.
Notably, this banner seemed to be exclusive to the Gmail desktop client, with no similar reports from Gmail's mobile app or G-Suite (Google Workspace) accounts. This distinction further narrowed down the potential causes, pointing towards an issue specific to the desktop interface or its integration with the wider Gmail system.
The specific wording of the banner often indicated a general caution or unverified status, which could easily be confused with other, more specific warnings that Gmail sometimes displays, such as a “This message seems dangerous” warning. However, the key differentiator was its pervasive nature across all incoming emails, regardless of the sender's reputation or the email's content.
The cause: a confirmed Gmail bug
After a period of confusion among users, the cause was officially confirmed to be a software bug within Gmail. Google acknowledged the issue on its Google Workspace Status Dashboard, indicating that the banner was appearing due to an internal system error rather than any malicious activity or a new policy enforcement. This provided much-needed clarity for those impacted.
The bug caused Gmail's system to incorrectly flag all emails, regardless of their source or content, with this warning. This was not related to sender reputation, authentication failures, or the content of the emails themselves. It was a temporary malfunction that affected the display logic for email messages on the desktop interface, as documented by various tech publications like Chrome Unboxed.
It's important to distinguish this type of bug from typical deliverability issues, which often stem from poor sender reputation, lack of proper email authentication (SPF, DKIM, DMARC), or content that triggers spam filters. In this specific case, the problem was entirely on Google's side, impacting even highly legitimate and frequently opened emails.
How it was resolved and its implications
The good news is that the unexpected banner issue was resolved relatively quickly by Google. As soon as the bug was identified and confirmed, their teams worked to deploy a fix, which rolled out and restored normal functionality for affected users. This swift resolution highlighted Google's commitment to maintaining a stable and trustworthy email environment.
For email marketers and businesses, this incident served as a reminder that even when all best practices are followed, external factors like software bugs can occasionally impact email display. It emphasized the importance of monitoring not just your own email metrics but also broader service status updates from major mailbox providers.
While this specific banner was a bug, it's a good prompt to review how Google authenticates emails and displays warnings when legitimate issues arise. Understanding email authentication protocols like SPF, DKIM, and DMARC is vital for ensuring your emails are trusted and delivered correctly, minimizing the chances of triggering real warning banners due to misconfigurations or security concerns.
Preventing similar issues in the future
Although the recent unexpected banner was a bug, email senders should always strive to maintain strong email deliverability practices to prevent legitimate warnings from appearing. Proactive measures can significantly improve your chances of reaching the inbox without issues. These practices often revolve around technical setup and content quality.
Authenticate your email: Ensure your domain has correctly configured SPF, DKIM, and DMARC records. These protocols verify your sender identity and help mailbox providers trust your emails, reducing the likelihood of warnings or rejections.
Monitor sender reputation: Regularly check your domain reputation through Google Postmaster Tools and other available tools. A poor reputation can lead to emails being marked as suspicious or landing in the spam folder.
Maintain a clean list: Remove inactive subscribers and address high bounce rates. Sending to unengaged or invalid addresses can harm your deliverability and lead to being placed on a blacklist or blocklist.
Optimize content: Avoid common spam triggers in your email content, subject lines, and links. Ensure your emails are well-formatted and provide clear value to recipients. Issues like image loading problems or invalid HTML syntax can also cause issues.
By adhering to these best practices, senders can significantly reduce the chances of encountering deliverability issues, whether they are due to a temporary glitch or a fundamental problem in their email program.
Views from the trenches
Best practices
Actively monitoring the Google Workspace Status Dashboard is critical for early detection of widespread email issues.
Implementing a robust DMARC policy with reporting helps in understanding email authentication failures that could lead to warnings.
Segment your email lists and send highly relevant content to improve engagement and maintain positive sender reputation.
Common pitfalls
Panicking and making drastic changes to email campaigns or infrastructure without first confirming the root cause.
Assuming an unexpected banner is due to your own email practices rather than a potential system-wide bug from the ESP.
Neglecting to monitor Google's official status pages for incidents, leading to delayed awareness of widespread issues.
Expert tips
If you see unusual behavior, check official status pages first.
Keep your email authentication records up to date.
Engage in list hygiene to prevent reputation damage.
Marketer view
Marketer from Email Geeks says they also observed the unexpected banner for some emails opened on Gmail desktop.
2022-07-06 - Email Geeks
Marketer view
Marketer from Email Geeks says they saw the banner appearing on every email opened in the inbox, including transactional, newsletter, triggered, and marketing communications.
2022-07-06 - Email Geeks
Summary of the incident
The appearance of an unexpected banner in Gmail desktop was indeed a temporary glitch caused by an internal software bug, and Google swiftly resolved the issue. While this particular incident was an anomaly, it underscores the dynamic nature of email deliverability and the importance of staying informed.
For email senders, it's a valuable reminder to consistently uphold strong email security and deliverability practices. By ensuring proper authentication, maintaining a healthy sender reputation, and monitoring relevant status dashboards, you can minimize disruptions and ensure your messages reliably reach their intended inboxes.
