# Checking for quarantined EAS devices

Source: https://developer.nylas.com/docs/unlisted/microsoft/quarantined-eas-devices/

Sometimes, authentication or syncing fails for a specific email account. When this happens, it might be because the ActiveSync protocol is causing the end user's email server to block access. This is the protocol Nylas uses to sync data from various Microsoft services.

Follow these steps to check for quarantined devices:

1. Log in to the Microsoft Exchange Admin center.
2. Select **Mobile** in the left navigation.
3. Under **Quarantined devices**, verify that no devices are listed.
4. Enable **Mobile device provisioning**.
5. Make sure your access rules don't conflict with [Nylas' suggested Microsoft 365 settings](/docs/provider-guides/microsoft/microsoft-365-settings/).
6. In the left navigation, select **Protection**.
7. Navigate to **Action center** and verify no accounts are impacted by the protection system.
8. Navigate to **Quarantine** and verify that no devices have been blocked or quarantined.