A bug in the Gmail app on Android is blocking Microsoft 365 and Exchange Online accounts from authenticating, cutting off work email access for a growing number of users across dozens of device brands. As Piunika Web first reported on May 6, 2026, affected users are finding that the Gmail app refuses to authenticate their Microsoft 365 or Exchange Online accounts, effectively locking them out of work email on their phones. Reports have been building up in a Reddit thread on r/Gmail with users chiming in from Pixel 7, 8, 9, and 10 devices, as well as Samsung S24, Sony Xperia, OnePlus, Xiaomi, and Motorola handsets.
The scale is significant. One IT consultant in the thread said the issue was hitting over 500 end users across 50 companies they support.
What Users Are Experiencing
The error message Gmail displays reads: "Check your account info or switch to modern authentication below. If you need help, contact your IT admin." Several users noted that the app then prompts for a password it simply rejects, regardless of what is entered.
Attempting to fix it by removing and re-adding the account makes things worse. Even stranger, deleting the account and trying to re-add it compounds the problem, with at least one commenter reporting they could not get their account back into Gmail at all after removing it.
The issue has since evolved into a persistent loop for many users, with the Gmail app pushing a "Credentials needed" notification every five minutes. Tapping the alert flashes a blank screen before dropping users right back where they started.
A recent Gmail app update (version 2026.04.27.910758475.Release) provides a false sense of security, as users confirm the credential prompt inevitably returns within 12 hours of installation.
This specific behavior appears to be hitting users with custom GoDaddy email addresses hosted by Exchange particularly hard.
The Root Cause: Microsoft's EAS 16.1 Enforcement
The technical fault line runs between Google and Microsoft's authentication infrastructure. Gmail uses Exchange ActiveSync (EAS) to sync mail, calendar, and contacts with Exchange accounts.
Starting March 1, 2026, Microsoft began blocking devices running ActiveSync versions lower than 16.1 from connecting to Exchange Online. EAS 16.1 was released as part of Exchange Server and Exchange Online in June 2016. According to the Microsoft Tech Community blog, both the Gmail app and the Samsung Mail app were acknowledged as "working on updating their apps now," with users advised to keep them up to date.
That update, however, has clearly not landed cleanly. Outlook for Android uses Microsoft's own REST-based sync protocol and is completely unaffected by the EAS enforcement.
While Google has not issued a formal statement, a Product Expert on the Gmail Community forums has acknowledged the situation as a distinct authentication compatibility problem with Microsoft Exchange.
The Damage Extends Beyond Email
For business owners and marketing teams, the fallout goes well beyond a missed inbox. The scope of the bug extends beyond email access: because the Gmail app uses Exchange ActiveSync to handle data across the entire Android OS, affected users are reporting that work contacts and joint calendars have disappeared from native system apps such as Samsung Calendar.
That means sales teams lose contact sync, marketing teams lose shared calendar access, and anyone relying on mobile-based CRM workflows tied to Exchange may find their data suddenly unavailable on their device.
The stakes are real at scale. According to DemandSage, 90% of U.S. startups and over 60% of mid-sized companies rely on Gmail, and 84% of users access Gmail via mobile devices. Any disruption to Exchange connectivity inside the Gmail Android app touches a wide cross-section of the business email ecosystem.
What You Can Do Right Now
For now, the only stable workaround most users recommend is switching to Outlook for Android, which is not an ideal outcome for users who specifically chose Gmail to keep everything in one place.
If you do switch to Outlook temporarily, there is one additional step to take. Users relying on the Outlook workaround should manually enable contact and calendar sync within the Outlook app's settings to restore missing data to their device.
For IT administrators managing affected Microsoft 365 tenants, the Microsoft Q&A forum advises affected users to continue using Outlook Mobile or Outlook Web as a workaround, since those clients use a different authentication and sync mechanism that is not impacted by this issue.
Neither Google nor Microsoft has issued a public statement on the issue at the time of writing. Until one of the two vendors pushes a confirmed fix, business teams running Android devices with Exchange-hosted email should audit their mobile setups and have a contingency client ready.
