Not keeping tabs on Microsoft 365 inactive mailboxes can lead to severe security vulnerabilities, compliance gaps, and unnecessary licensing costs. However, no need to worry! We've got you covered with our practical solutions to find and manage inactive mailboxes in Exchange Online. Act now for a secure Exchange Online environment!
Windows PowerShell Connect-ExchangeOnline -UserPrincipalName <UPN> Windows PowerShell Get-Mailbox -ResultSize Unlimited | Foreach{Get-MailboxStatistics -Identity $_.UserPrincipalName | Select DisplayName,LastLogonTime,LastUserActionTime} 
The AdminDroid Exchange Online management tool helps you to find and manage inactive mailboxes in your Microsoft 365 environment by providing reports on mailbox usage, as well as information on holds and retention policies applied to them.
Keep an eye on mailbox owner access logs to find whether the mailboxes in your Exchange Online environment are being used regularly.
Look into the mailbox login activities in your Microsoft 365 environment to prevent unauthorized access and meet compliance requirements.
Easily monitor DLP policy matches to prevent leakage of sensitive information from Exchange Online mailboxes.
Ensure that any personal information in inactive mailboxes is handled in compliance with GDPR requirements with AdminDroid.
Access comprehensive mailbox usage reports seamlessly from a centralized hub, thereby streamlining Exchange mailbox management.
Get a complete information of Exchange Online mailboxes in a single place and manage each mailbox activity in your organization.
AdminDroid transforms the intricate task of managing inactive mailboxes into a breeze for Exchange Online admins. Its sophisticated reporting capabilities empower you to take proactive measures, such as disabling mailboxes, assigning different retention policies, and restoring inactive mailboxes.
This error occurs when you don’t have sufficient permission to read the inactive mailboxes in Exchange Online.
Add-RoleGroupMember -Identity "View-Only Recipients" -Member <UserDisplayName>
This error occurs when you try to disable a mailbox configured with a retention policy.
Set-Mailbox <IdentityofInactiveMailbox> -ExcludeFromAllOrgHolds
This error occurs if the target mailbox has a disabled archive while restoring an inactive archive mailbox.
Enable-Mailbox -Identity <UserPrincipalName> -Archive
This error occurs when you have not connected to the Exchange Online PowerShell.
Connect-ExchangeOnline -UserPrincipalName <YourAdminAccount>
This error occurs when the Exchange GUID of the mailbox is wrong.
Get-Mailbox -Identity <MailboxIdentity> | Format-List *GUID,MailboxLocations
Inactive mailboxes are used to retain former employee’s data to preserve sensitive information after they leave the Microsoft 365 organization.
You can create inactive mailboxes to retain mailbox content indefinitely by deleting the user account configured with Microsoft 365 retention policies or holds. Follow the steps below to configure the Microsoft 365 retention policy for an Exchange Online mailbox.
After configuring the data retention policy for a user’s Exchange Online mailbox who is leaving your organization, you can delete the Microsoft 365 user account using PowerShell.
Remove-MgUser –UserId "<UserObjectID>"How to identify the type of hold placed on an Exchange Online mailbox?
Using AdminDroid, you can check if a mailbox is on hold and remove unnecessary holds or retention policies before deleting a Microsoft 365 user account.
You can restore the inactive Exchange Online mailbox of an ex-employee and provide mailbox content access to other active users in your Microsoft 365 organization. Follow the steps below to restore an inactive mailbox in Office 365.
Connect-ExchangeOnline -UserPrincipalName <UPN>$inactiveMailbox = Get-Mailbox -InactiveMailboxOnly -Identity <ExchangeGuid of inactive mailbox>$inactiveMailbox.LegacyExchangeDNSet-Mailbox <ExchangeGuid of target mailbox> -EmailAddresses @{Add=X500:"<LegacyExchangeDN of inactive mailbox>"New-MailboxRestoreRequest -SourceMailbox $inactiveMailbox.DistinguishedName -TargetMailbox <ExchangeGuid of target mailbox>Get-MailboxRestoreRequest | Select-Object DisplayName, IdentityGet-MailboxRestoreRequest -Identity <Identity of the desired mailbox restore request>Pro Tip: When an Exchange Online inactive mailbox is restored, only the contents are copied to another mailbox. However, it is still considered as an inactive mailbox and can be searched using eDiscovery.
Using AdminDroid, you can audit the mailbox restoration activities performed in your Exchange Online environment.
You can recover a former employee’s inactive mailbox by granting access to a new Microsoft 365 user in your organization. This process converts the inactive mailbox into an active mailbox that contains all the recovered contents.
Connect-ExchangeOnline -UserPrincipalName <UPN>$inactiveMailbox = Get-Mailbox -InactiveMailboxOnly -Identity <ExchangeGuidofInactiveMailbox>New-Mailbox -InactiveMailbox $InactiveMailbox.DistinguishedName -Name <Name> -FirstName <First name> -LastName <Last Name> -DisplayName "<Display Name>" -MicrosoftOnlineServicesID <User Principal Name> -Password (ConvertTo-SecureString -String '<Password>' -AsPlainText -Force) -ResetPasswordOnNextLogon $trueAfter recovering an inactive mailbox, a new Microsoft 365 user account is created in your organization. To activate this account, simply assign a license through your Microsoft 365 admin portal.
Note: When you recover an inactive mailbox, it gets completely converted to an active mailbox and is linked to a new user account. Subsequently, it is no longer classified as inactive.
An Exchange Online mailbox can become inactive if a Microsoft 365 retention policy or hold is applied to it before deleting the user account. To manage these deleted mailboxes efficiently, get the Exchange Online inactive mailbox report and remove any holds or retention policies once the mailbox content is no longer required to be retained.
Get-Mailbox -InactiveMailboxOnly -ResultSize Unlimited | FT DisplayName,PrimarySMTPAddress,WhenSoftDeletedWith AdminDroid, you can easily find deleted mailboxes in Exchange Online and remove the retention policies or holds applied if you don’t need to retain their contents.
Once you no longer require the contents of an inactive mailbox, you can permanently delete the mailbox by removing all holds on it. Subsequently, the inactive mailbox is automatically flagged for deletion and will be permanently removed after processing.
Before removing the holds, you must identify the type of hold placed on an Exchange Online mailbox. You can identify them by running the below cmdlets in your Exchange Online PowerShell.
Get-Mailbox -Identity <IdentityofInactiveMailbox> -InactiveMailboxOnly | FL DisplayName,Name,DistinguishedName,ExchangeGuid,IsInactiveMailbox,LitigationHoldEnabled,LitigationHoldDuration,LitigationHoldDate,LitigationHoldOwner,InPlaceHolds,ComplianceTagHoldAppliedRun the below PowerShell cmdlet to remove an inactive mailbox from a retention policy that is configured at the organization level.
Set-Mailbox <Identity of inactive mailbox> -ExcludeFromOrgHolds <Retention policy GUID without prefix or suffix>You can also remove an inactive mailbox from all the retention policies configured at the organization level.
Set-Mailbox <Identity of inactive mailbox> -ExcludeFromAllOrgHoldsRun the below PowerShell cmdlet to remove an inactive mailbox from a retention policy configured for specific mailboxes.
Set-RetentionCompliancePolicy -Identity <Retention policy GUID without prefix or suffix> -RemoveExchangeLocation <Identity of inactive mailbox>Run the below PowerShell cmdlet to remove a Litigation hold from an inactive mailbox.
Set-Mailbox -InactiveMailbox -Identity <Identity of inactive mailbox> -LitigationHoldEnabled $false
After removing the holds or retention policies on an inactive mailbox, it is considered a soft-deleted mailbox and is marked for permanent deletion after 30 days.
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