MailStore – Microsoft 365: “Error Message AADSTS50105” When MailStore sign in Microsoft 365 with modern Authentication
Summary
When MailStore sign in Microsoft 365 with modern Authentication (OAuth), an Error Message AADSTS50105 occurs.
Cause
This is a third-party issue and cannot be resolved by MailStore.
The following error occurs, when MailStore sign in via Microsoft 365 modern Authentication (OAuth)
Error:
Error Message AADSTS50105 during Sign in via Microsoft 365 modern Authentication (OAuth)
AADSTS50105: Your administrator has configured the application <APPNAME created for MailStore Modern Authentication> to block users unless they are specifically granted (‘assigned’) access to the application. The signed-in user ‘azure-username’ is blocked because they are not a direct member of a group with access, nor had access directly assigned by an administrator. Please contact your administrator to assign access to this application.
Resolution
Solution
- Sign in to portal.azure.com with an administrative account
- Navigate to the “Azure Active Directory” overview and then select “Enterprise applications”. (You can also use the below link)
https://aad.portal.azure.com/#view/Microsoft_AAD_IAM/StartboardApplicationsMenuBlade/~/AppAppsPreview - Select the App that you created for MailStore Modern Authentication.
- In the menu on the left, select “Properties”.
- Set “Assignment required?” to “No”
Background information:
The signed-in user has not been granted access to the MailStore app in the Azure Control Panel.