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Druva Documentation

Troubleshoot EUSERNOTFOUND error during backup of Exchange Online and OneDrive

This article applies to:

  • Product edition: inSync Cloud

Problem description

During the backup of the Microsoft 365 data for Exchange Online and OneDrive apps, inSync shows an error EUSERNOTFOUND.

This article discusses the scenarios arising with different user configurations on Exchange Online and OneDrive and provides the resolution steps for each.

Cause

By default OneDrive is mapped to the Username parameter in Microsoft 365, which cannot be changed. Exchange online, on the other hand can either match the email to the Username or it can be separate from the username.  If the email address does not match the username, the username is added as an email alias under Exchange Online. You cannot remove the alias entry for the username from Exchange online.

Scenario-1: Email address and UPN is same for inSync user and Microsoft 365

inSync email ID AD/LDAP name ID to access user accounts  Exchange online email/SMTP Exchange Online alias/SMTP OneDrive UPN (User Principal Name) Exchange Online Backup status OneDrive Backup status
Brian.Connor@druva365.tk Brian.Connor@druva365.tk inSync email Brian.Connor@druva365.tk Brian.Connor@druva365.tk Brian.Connor@druva365.tk Backup successful Backup successful
Brian.Connor@druva365.tk Brian.Connor@druva365.tk UPN Brian.Connor@druva365.tk Brian.Connor@druva365.tk Brian.Connor@druva365.tk Backup successful Backup successful

UserSummary.png

 

EmailUPNSame.png

 

Since the user email ID and UPN is same in inSync and Microsoft 365, you can match either the email ID or UPN against that of Microsoft 365 using the following steps:

To change these settings:

  1. On the inSync Management Console menu bar, click Data Sources > Microsoft 365.
  2. On the Overview page click More options icon.png  and then click Settings. The Cloud App Settings dialog box appears. By default, the Access user accounts using is configured to inSync Email ID is selected.

Cloud App Settings_Oct6.png

  1. Check the backup status in inSync for Exchange Online and OneDrive where backup is successfully completed.

    Scenario11 (1)_rebranding.png
  2. Switch the Access user accounts using setting to AD Attribute and set it to User Principal Name (UPN)

    CloudAppSetting2.png
    inSync backup succeeds as email address and UPN is same for inSync and Microsoft 365.

    Scenario12_rebranding.png

Scenario-2: Email address and UPN is different for the inSync user

When the email address and UPN are different for an inSync user, but same for corresponding Microsoft 365 user, you can match either the email ID or UPN against Microsoft 365 to validate the user.

inSync email ID AD/LDAP name ID to access user accounts  Exchange online email/SMTP Exchange Online alias/SMTP OneDrive UPN (User Principal Name) Exchange Online Backup status OneDrive Backup status
Brian.C@druva365.tk Brian.Connor@druva365.tk inSync email Brian.Connor@druva365.tk Brian.Connor@druva365.tk Brian.Connor@druva365.tk EUSERNOTFOUND EUSERNOTFOUND
Brian.C@druva365.tk Brian.Connor@druva365.tk UPN Brian.Connor@druva365.tk Brian.Connor@druva365.tk Brian.Connor@druva365.tk Backup successful Backup successful

UserSummary2.png

EmailUPNDiff.png

To configure these settings:

  1. On the inSync Management Console menu bar, click Data Sources > Microsoft 365.
  2. On the Overview page click More options icon.png  and then click Settings. The Cloud App Settings dialog box appears. By default, the Access user accounts using is configured to inSync Email ID is selected.

Cloud App Settings_Oct6.png
Since, Email address in inSync is Brian.c@druva365.tk and username/email in Microsoft 365 is Brian.connor@druva365.tk, backup fails for both OneDrive as well as Exchange Online.

Scenario12_rebranding.png

  1. Switch the Access user accounts using setting to AD Attribute and set it to User Principal Name (UPN)

    Cloud App Settings_Oct6.png
    Since, AD/LDAP name in inSync is Brian.connor@druva365.tk and username/email in Microsoft 365 is Brian.connor@druva365.tk, inSync Backup will be successfully completed as inSync will able to find user in Microsoft 365 using UPN.

    Scenario22_rebranding.png

Scenario 3: Username and Email Address are different in inSync and Microsoft 365

In this scenario, the inSync email ID matches the Microsoft 365 email address. Similarly, the inSync AD/LDAP username matches the Username in Microsoft 365. However, the email address and username do not match each other in both inSync and Microsoft 365.

inSync email ID AD/LDAP name ID to access user accounts  Exchange online email/SMTP Exchange Online alias/SMTP OneDrive UPN (User Principal Name) Exchange Online Backup status OneDrive Backup status
Brian.C@druva365.tk Brian.Connor@druva365.tk inSync email Brian.C@druva365.tk Brian.Connor@druva365.tk Brian.Connor@druva365.tk Backup successful EUSERNOTFOUND
Brian.C@druva365.tk Brian.Connor@druva365.tk UPN Brian.C@druva365.tk Brian.Connor@druva365.tk Brian.Connor@druva365.tk Backup successful Backup successful

To validate the user from inSync, you can match either the email ID or UPN with the one in Microsoft 365.

UserSummary3.png

UserNEmailDiff.png

To configure these settings:

  1. On the inSync Management Console menu bar, click Data Sources > Microsoft 365.
  2. On the Overview page click More options icon.png  and then click Settings. The Cloud App Settings dialog box appears. By default, the Access user accounts using is configured to inSync Email ID is selected.

Cloud App Settings_Oct6.png

Since email address for inSync user brian.c@druva365.tk and Exchange mailbox is same, the backup is successful.

Scenario31_rebranding.png
Since OneDrive is only mapped to UPN, its authentication fails when it is validated against inSync email. 

Scenario32_rebranding.png

  1. Switch the Access user accounts using setting to AD Attribute and set it to User Principal Name (UPN)

    Cloud App Settings_Oct6.png
    Here, AD/LDAP name in inSync is Brian.connor@druva365.tk and email aliases in Exchange Online is Brian.connor@druva365.tk, inSync Backup succeeds as inSync is able to find the user in Microsoft 365 using email aliases.

    Scenario33_rebranding.png
    Since, AD/LDAP name in inSync is Brian.Connor@druva365.tk and Username in OneDrive is Brian.Connor@druva365.tk, inSync backup succeeds as inSync is able to find the user in Microsoft 365 using email aliases.

    Scenario34_rebranding.png