Note When users are created in Azure AD, their user principal name (UPN) will also be used as one of the SMTP proxy addresses. Therefore, the SMTP proxy address will also contain the number.
Additionally, you may see one of the following messages:
- In the Office 365 portal:There is an error on one or more user accounts. To see which users are affected and the detailed error message, select the "users with errors" view, and then click the user’s display name.[DIRSYNC ERROR]: This User has been synced to your Azure Active Directory, but we had to modify the UserPrincipalName property from email@example.com to firstname.lastname@example.org because an existing user, email@example.com, was already created with this firstname.lastname@example.org to email@example.com because an existing user, firstname.lastname@example.org, was already created with this value.
- From an email report:This object has been updated in your Azure Active Directory, but with some modified properties, because the following attributes are associated with another object [UserPrincipalName email@example.com;].
Step 1: Check your local directoryUse the IdFix DirSync Error Remediation Tool to identify duplicate or invalid attributes.
To resolve duplicate attributes by using the IdFix Tool, see the following Microsoft Knowledge Base article:
Step 2: Check Azure ADYou can use the Office 365 portal or the Azure Active Directory Module for Windows PowerShell to check Azure AD for duplicate attributes.
Method 1: Use the Office 365 portal
- Sign in to the Office 365 portal (https://portal.office.com) as an administrator.
- In the Office 365 admin center, go to Users, and then click Active users.
A warning at the top of the page is displayed if there are duplicate attribute conflicts on any object in your organization.
- Click an object to view details about the conflict. This information is displayed in the lower-right corner of the page.
- Change the user name so that it's unique.
Method 2: Use the Azure AD Module for Windows PowerShellTo learn more about how to use the Azure AD Module for Windows PowerShell to identify objects that have duplicate values, see Identity synchronization and duplicate attribute resiliency.
Article ID: 3166795 - Last Review: Dec 21, 2016 - Revision: 1