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The Index of the different Exchange Online mailbox restores methods| Part 5#23

The current article serves as an index, for the different Exchange Online mailbox restore scenarios, which appear along the current article series that include 23 articles.

The purpose of this “index” is, to help you to quickly and efficiently locate the specific Exchange Online mailbox restore scenario that you need to deal with, and to find the particular article, which will provide you the steps for implementing the required Exchange Online mailbox restore process.

The information about the Exchange Online mailbox restore scenarios is divided into two groups:

  1. Exchange Online mailbox restores scenario in Office 365 “cloud only” environment.
  2. Exchange Online mailbox restores scenario in Office 365 + Directory synchronization environment.

Why do we need to use the index of “Exchange Online mailbox restore methods”?

The subject of restoring Exchange Online mailbox in Office 365 “cloud only” environment and in Office 365 and Directory synchronization environment, can be quite confusing because of a couple of reasons:

Reason 1 – Different type of Exchange Online restore mailbox options

Exchange Online provides a couple of methods that we can use for restoring Soft Deleted Exchange Online mailbox.

Each of the restore methods has a particular character, concrete steps that need to implemented and specific advantages and disadvantages.

Reason 2 – Office 365 and Directory synchronization based environment

The configuration of Office 365 + Directory synchronization infrastructure, can be considered as a complicated environment.

The “right method” for restoring deleted Exchange Online mailbox in such environment, is based on a very simple concept – restoring the On-Premise Active Directory user account that considers as the “root” for all the “another connected object” in the Directory synchronization environment.

Many times, this best practice is not implemented and instead, the Exchange Online mailbox restore process performed improperly.

In this scenario, we will need to understand the “Restore mailbox mistake” + choosing the “right tool” for fixing the restore mistake.

Dealing with the confusing Exchange Online mailbox restore scenario

The Office 365 infrastructure can be implemented using one of the following ways:

Scenario 1 – Cloud only (Fully Hosted) environment

“Native” Office 365 environment, that uses the Office 365 Directory services (Azure Active Directory) and the Exchange Online infrastructure, without any connection or relationship with the on-Premises environment (On-Premise Active Directory or On-Premise Exchange).

Scenario 2 – Directory synchronization and Exchange Hybrid environment

This type of Office 365 implementation, includes a “logical binding” between the On-Premise Active Directory infrastructure and the Azure Active Directory.

Exchange Online mailbox restore - Office 365 environment clarification -01

A. Cloud only (Fully Hosted) environment | Exchange Online mailbox restores options

In this type of Office 365 implementation, there are three restore Exchange Online mailbox options, but, at the current time, only two restore options can be implemented:

1. Restoring the Office 365 user account (Mailbox owner)

This is the “preferred” restored Exchange Online mailbox option. The restore process is implemented by, just restore the Office 365 user account that considered as the Exchange Online mailbox owner.

2. Restoring the Exchange Online Mailbox and creating NEW Office 365 user account (Undo-SoftDeletedMailbox)

This is the least preferred option, in which we use a PowerShell command that executes the following set of tasks:

  • Restore the Soft Deleted Exchange Online mailbox.
  • Create a NEW Office 365 user account.
  • Bind the restored Exchange Online mailbox to the NEW Office 365 user account.

3. Restoring the Exchange Online Mailbox and connecting the Exchange Online mailbox to the original user account that considers as the mailbox owner

This option can regard as a “theoretically option.”
Although this restore option can be implemented, at the current time, from my own personal experience, I strongly recommended not to use this option, because this method can lead to a scenario of “unrecoverable Exchange Online mailbox.”

You can read more information about this issue in the following article – What are the possible options for recovering Exchange Online mailbox? | Part 4#23

Cloud only -Fully Hosted environment -02

B. Directory synchronization and Exchange Hybrid environment

The “recommended” (best practice) methods for restoring deleted Exchange Online mailbox

In Office 365 and Directory synchronization environment, most of the time the preferred restored method of Soft Deleted Exchange Online mailbox is the following method:

Method 1#2 – Restoring the Soft Deleted On-Premise Active Directory user account, that is “bound” to the Soft Deleted Office 365 user account (the Office 365 users consider as the owner of the Soft Deleted Exchange Online Mailbox).

Method 2#2 – Restoring Exchange Online mailbox content to another mailbox, using PowerShell command New-MailboxRestoreRequest

Another option that we can use is – restoring the “content” of Soft Deleted Exchange Online mailbox to existing active Exchange Online mailbox (vs. the previous method of restoring the Exchange Online mailbox).

This type of solution implemented by using PowerShell command named New-MailboxRestoreRequest that enabled us to “Ship” mailbox content from Exchange Online Mailbox A to Exchange Online Mailbox B.

In our scenario, copy the content of Soft Deleted Exchange Online mailbox to existing “active” Exchange Online mailbox.

Directory synchronization and Exchange Hybrid environment -03

Dealing with Exchange Online mailbox restore process that was implemented improperly in Directory synchronization environment

As mentioned, in Office 365 and Directory synchronization, there is “specifically recommended method,” for restoring Soft Deleted Exchange Online mailbox.

The “issue” is that many times, the Exchange Online mailbox restore scenario implemented Improperly.

For this reason, we will need to “identify” the specific restore mistake that executed, and choose the right solution that needs to implemented.

Dealing with Exchange Online mailbox restore process that was implemented Improperly -04

The article series table of content

To be able to get a “high-level view” of the different scenarios of Exchange Online restore scenario in the different environment, you can use the following table

Restore Exchange Online mailbox in Cloud only (Fully hosted) environment | Scenarios table

Restoring Exchange Online User mailbox

Scenario 1#2 – Restore the Office 365 user account (the mailbox owner).
Exchange Online mailbox restore process
The user account restores procedure, can be implemented by using the Office 365 admin center interface (web-based based interface).
Restoring the Soft Deleted Office 365 user account will restore the Exchange Online license that assigned to the user account.
The restore of the Exchange Online license will lead to the automatic restore process of the Soft Deleted Exchange Online mailbox.
You can read detailed information about this Exchange Online mailbox restore process in the article – Restore Exchange Online user mailbox | Cloud only (Fully Hosted) environment | Article 1#3 | Part 8#23
Scenario 2#2 – Restring the Exchange Online User Mailbox, and creating NEW Office 365 user account (using the PowerShell command – Undo-SoftDeletedMailbox).
Exchange Online mailbox restore process
This is the least preferred option, in which we use PowerShell command, that restore the Soft Deleted Exchange Online user mailbox + create a NEW Office 365 user account + Bind the restored Exchange Online mailbox to the NEW Office 365 user account.
You can read detailed information about this Exchange Online mailbox restore process in the article – Restore Exchange Online user mailbox | Cloud only (Fully Hosted) environment | Article 3#3 | Part 10#23

Restoring Exchange Online Shared mailbox

Scenario 1#2 – Restore the Office 365 user account (the Shared mailbox owner).
Exchange Online mailbox restore process
The user account restore procedure can be implemented by using the Office 365 admin center interface (web-based based interface).
Restoring the Soft Deleted user account that considers as the Shared mailbox owner, will automatically restore the Soft Deleted Shared Exchange Online mailbox.
You can read detailed information about this Exchange Online mailbox restore process in the article – Restore Exchange Online Shared mailbox | Cloud only (Fully Hosted) environment | Part 7#23
Scenario 2#2 – Restring the Exchange Online Shared Mailbox and creating NEW Office 365 user account (using the PowerShell command – Undo-SoftDeletedMailbox).
Exchange Online mailbox restore process
This is the least preferred option, in which we use PowerShell command, that restore the Soft Deleted Exchange Online mailbox + create a NEW Office 365 user account + Bind the restored Exchange Online mailbox to the NEW Office 365 user account.
You can read detailed information about this Exchange Online mailbox restore process in the article – Restore Exchange Online Shared mailbox | Cloud only (Fully Hosted) environment | Part 7#23

Restoring Exchange Online Room mailbox

Scenario 1#2 – Restore the Office 365 user account (the Room mailbox owner).
Exchange Online mailbox restore process
The user account restore procedure can implemented by using the Office 365 admin interface (web-based interface).
Restoring the Soft Deleted user account that considers as the Room mailbox owner, will automatically restore the Soft Deleted Room Exchange Online mailbox.
You can read detailed information about this Exchange Online mailbox restore process in the article –Restore Exchange Online Room mailbox | Cloud only (Fully Hosted) environment | Part 6#23
Scenario 2#2 – Restring the Exchange Online Mailbox and creating NEW Office 365 user account (using the PowerShell command – Undo-SoftDeletedMailbox).
Exchange Online mailbox restore process
This is the least preferred option, in which we use PowerShell commands that restore the Soft Deleted Exchange Online mailbox + create a NEW Office 365 user account + Bind the restored Exchange Online mailbox to the NEW Office 365 user account.
You can read detailed information about this Exchange Online mailbox restore process in the article – Restore Exchange Online Room mailbox | Cloud only (Fully Hosted) environment | Part 6#23

Another type of Exchange Online mailbox restores scenarios

The Exchange Online license that was assigned to Office 365 user was removed
The Exchange Online mailbox will be considered as Soft Deleted Exchange Online mailbox and will be saved over a period of 30 days in the Exchange Online recycle bin.
Note – at the current time, although the Exchange Online mailbox will be saved in the Exchange Online recycle bin, there is no option for display information about the Soft Deleted Exchange Online mailbox.
Restore procedure
Very simple, all you need to do is just assign back the Exchange Online license to the Office 365 user and the Exchange Online mailbox will be restored automatically.

Restore Exchange Online mailbox in Directory synchronization and Exchange Hybrid environment | Scenarios table

The “recommended” (best practice) methods for restoring deleted Exchange Online mailbox

Method 2#2 – Restoring Exchange Online mailbox content to another mailbox, using PowerShell command New-MailboxRestoreRequest

Another option that we can use is implemented by using PowerShell command named –
New-MailboxRestoreRequest that enables us to “Ship” mailbox content from Exchange Online Mailbox A to Exchange Online Mailbox B. In our scenario, copy the content of Soft Deleted Exchange Online mailbox to existing “active” Exchange Online mailbox.

Restoring Exchange Online User mailbox in Directory synchronization environment

Method 1#2 – Restring the On-Premise Active Directory user account, that is “bound” to the Office 365 user account (Office 365 users who considered as the Exchange Online Mailbox owner).
In Directory synchronization environment, the best solution most of the times is, to restore the Soft Deleted On-Premise Active Directory user account.
You can read detailed information about this Exchange Online mailbox restore process in the article – Restore Exchange Online USER mailbox | Directory synchronization environment | The “right way” | Part 17#23
In case that you need more information about the methods for restoring Soft Deleted Active Directory user account in case that the Active Directory recycle bin was not enabled, you can read the following articles:
In case that you need more information about the methods for restoring Soft Deleted Active Directory user account in case that the Active Directory recycle bin was enabled, you can read the following article:
How to restore Active Directory deleted user account by using Active Directory recycle bin | Article 4#4 | Part 16#x
Method 2#2 – Restoring Exchange Online mailbox content to another mailbox, using PowerShell command – New-MailboxRestoreRequest
Another option that we can use is implemented by using PowerShell command named –
New-MailboxRestoreRequest that enables us to “Ship” mailbox content from Exchange Online Mailbox A to Exchange Online Mailbox B. In our scenario, copy the content of Soft Deleted Exchange Online mailbox to existing “active” Exchange Online mailbox.
You can read detailed information about this Exchange Online mailbox restore process in the article – Restoring Exchange Online mailbox content to another mailbox using PowerShell command New-MailboxRestoreRequest | Part 22#23

Dealing with Exchange Online mailbox restore process that was implemented Improperly in Directory synchronization environment

Mistake A – Instead of restoring the original On-Premise Active Directory user account that was deleted, a NEW Active Directory user account is created that is seemingly identical to the “original user” because he has the same login name, the same E-mail address, etc.
In the article – Reviewing the characters of Exchange Online mailbox recovery mistake – New On-Premise Active Directory User Account was created | Part 19#23, and in the article – Prefix – the “Problematic” Exchange Online mailbox restores scenarios in Directory synchronization environment | Part 18#23, include detailed descriptions, about the characters and the causes for this type of Exchange Online mailbox restore mistake.
Offered solutions
Two possible solutions can be implemented to solve this Exchange Online mailbox restore mistake in Directory synchronization environment.
Optional solution 1#2 – Revert the restore mistake
1 – Delete the NEW On-Premise Active Directory User Account.
2 – Synchronize the information to the cloud.
3 – Restore the “Original” On-Premise Active Directory User account.
4 – Synchronize the information to the cloud.
In the article – Solving an Exchange Online mailbox restore mistake by Restoring the original Soft Deleted Active Directory user | Part 21#23, we review in details, the exact process that needs to be implemented, for solving this type of Exchange Online mailbox restore mistake.
Optional solution 2#2 – Copy the content of the Soft Deleted Exchange Online mailbox
Import the content of the Soft Deleted Exchange Online mailbox to the “New Empty” Exchange Online mailbox.”
In the article – Restoring Exchange Online mailbox content to another mailbox using PowerShell command New-MailboxRestoreRequest | Part 22#23, we review in details, the exact process that needs to be implemented, for solving this type of Exchange Online mailbox restore mistake.
Mistake B – Instead of restoring the “original” On-Premise Active Directory user account that was deleted, the Office 365 user who considers as the Exchange Online mailbox owner was restored.
In the article – Reviewing the characters of Exchange Online mailbox recovery mistake – Soft Deleted Office 365 was restored | Part 20#23,I will provide a detailed description, about the characters and the causes for this type of Exchange Online mailbox restore mistake.
Offered solution
Optional solution 1#1 – Encourage Directory Synchronization Soft Match
Remove the ImmutableID value from the Soft Deleted Office 365 user account
In the article – Solving an Exchange Online mailbox restore mistake Office 365 user was restored – removing the ImmutableID value | Part 23#23, we review in details, the exact process that needs to be implemented, for solving this type of Exchange Online mailbox restore mistake.

The next article in the current article series

Restore Exchange Online Room mailbox | Cloud only (Fully Hosted) environment | Part 6#23

o365info Team

o365info Team

This article was written by our team of experienced IT architects, consultants, and engineers.

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