Managing emails in Office 365 is like having a smart assistant: it can sort, store, and even delete messages on its own, making life easier for administrators. If you're responsible for your organization's email, you know it's a big job. But with Office 365's advanced features, you can automate it all.

For example, the Messaging Retention Management tool, or MRM, lets you create rules that handle emails automatically—moving them to an archive or deleting them when they're old news.

This guide is your walk-through to setting up these smart rules, tagging emails you need to keep, and keeping your emails clean and organized. Get ready to take the hassle out of email management and have more time for the important things with Office 365's help.

Tasks that the administrator needs to perform for policy creation:

  1. Enable user’s archive mailbox

    Enable the archive mailbox for each user in the organization so that the retention tag will find it easier to move the objects in it. Also, the user can also archive information manually. It allows more storage space for the user’s data.

  2. Create retention tags as per the criteria
    • Move the messages which are older than 3 years from the primary mailbox to the archive mailbox. It will give you some free space in the primary one.
    • Delete the 5-year older messages from the deleted items folder permanently. This will free up some storage space and in fact these messages can be recovered at any given time.
    • Permanently delete the 7-year older messages from both archive and deleted items folder. Sometimes, businesses must follow the compliance regulations, but most of the time, 7 years is enough period to delete the messages permanently.
  3. Create custom retention policy

    Create user-defined retention tags to handle the content. These are custom tags that a user assigns to a specific message of the mailbox.

Steps to setup Office 365 archive policy and deletion policy

Setting up the MRM policy and Retention tag is a detailed process. But before we proceed to that, these are certain pre-requirements which are to be kept in mind-

  • Only a global admin can perform these procedures.
  • A default MRM policy is already in existence. The admin replaces it with the new one. Only one policy can be applicable at one time. Now, these are the steps which you need to conduct-
    1. Enable Users’ Archive Mailboxes
    2. Create new Retention tags for Archive & Deletion
    3. Create a new Retention Policy
    4. Assign new Policy to User Mailboxes
Step 1: Enabling archive mailboxes for users

Items residing in a user's mailbox, which exceed the specified archiving policy timeframe assigned to that mailbox, will automatically transfer to the new archive mailbox when it becomes active. By default, Exchange Online mailboxes incorporate a retention policy that mandates items sent or generated by a user will be moved to the archive mailbox two years after their creation or transmission date.

First and foremost, verify that every user possesses an active archive mailbox to facilitate the smooth execution of the 'Move to archive' retention tag. Here are the steps to get started:

  1. In Microsoft 365 Admin Center, go to Exchange Admin Center and click on it to open. Go to Exchange Admin Center
  2. In the Recipients category, select Mailboxes and from the available Mailboxes, choose a mailbox in which you want to enable Archive mailbox. Single-click on it. Choose a mailbox in which you want to enable Archive mailbox
  3. Go to the others section and open the Manage Archive Mailbox option. Open the Manage Archive Mailbox option
  4. Move the toggle from Off to On and Save the changes. Save the changes
Step 2: Creating retention tags for archive and deletion policies

In this step, we will create three distinct retention tags for the upcoming retention policy, encompassing both archiving and deletion. You have the flexibility to assign a name of your choice to these retention tags; for this guide, we will use the name "Kernel."

  • Kernel 3 year Move to Archive (Custom Archive Policy)
  • Kernel 7 year Permanently Delete (Custom Deletion Policy)
  • Kernel Deleted Items and Allow Recovery 5 years (Custom tag for Deleted items folders)
Kernel 3 year Move to Archive (Custom Archive Policy)

This tag will automatically move items older than 3 years to Archive mailboxes. To create the custom tag, just follow the steps:

  1. In the Office 365 admin center, click Admin Centers < Exchange. Click Admin Centers and Exchange
  2. In the Exchange Admin Center, go to Compliance Management and click Retention Tags. Click the + button and select the first option applied automatically to the entire mailbox (default). Click plus button and select the first option applied automatically
  3. On the new tag applied automatically to the entire mailbox (default) page, provide the required details like Name, Retention action – Move to Archive, Retention period – 1095 days (3 years) with Comment (optional). Click Save to save the entries. Retention action
Kernel 7 year Permanently Delete (Custom Deletion Policy)

This tag will permanently delete items after 7 years. To create a custom retention tag, perform the steps:

  1. In Exchange Admin Center > Compliance Management > Retention Tags, click the + button and select applied automatically to the entire mailbox (default). Create a custom retention tag
  2. It will open with a new tag applied automatically to the entire mailbox (default). Here, provide Name, select Retention action as Permanently Delete. Enter the Retention period as 2555 days (7 years). Then, click Save to save the settings for this Retention tag. Select Retention action as Permanently Delete
Kernel Deleted Items and Allow Recovery 5 years (Custom tag for Deleted items folders)

This tag will automatically delete folder items after 5 years. It also provides a recovery period in which the user can recover those items using the Recover Deleted Items feature.

  1. On the retention tags page, select applied automatically to a default folder option from the list now. Select applied automatically to a default folder option
  2. A page named new tag automatically applied to a default folder will open. Provide a Name, select Deleted items from the list, select Delete and Allow Recovery as Retention action, and enter 1824 days (5 years) as Retention period. Click Save to create this tag. Click Save to create this tag
Step 3: Creation of the retention policy

When you create an account in Office 365, a Default MRM Policy is created. You have to create a new retention policy and replace it with the Default MRM policy. First you should know about retention policy then creating a new retention policy, the user has to assign the created retention tags to it. Let us see how to create the retention policy and add retention tags to it.

  1. Go to Exchange Admin Center > Compliance Management > Retention Policies. Click the + button. Creation of the retention policy
  2. In the new retention policy page, enter a Name and then click the + (add) button under Retention tags. Click add button under Retention tag
  3. In select retention tags, select the three newly created retention tags. Along with them, select the following tags:
    • Junk Email
    • Never Delete
    • 1 Month Delete
    • 1 Year Delete
    • Personal 1 year move to archive
    • Recoverable items 14 days move to archive

    After the selection, click the add option to add the tags. Click OK to save the Retention tags.

    Click OK to save the Retention tags
  4. On the Retention policies page, select your created retention policy and click Save. You can view the tags linked to it within the right pane. Select your created retention policy and click Save
Step 4: Assign new retention policy to user mailboxes

This step requires assigning a new retention policy to the user mailboxes of the Office 365 account. Perform the steps below to do this:

  1. Navigate to the Exchange Admin Center, select Recipients, and then click Mailboxes. Select the user mailboxes you want to assign the policy and on the right-side panel, click More options and click Update for Retention Policy. Assign new Retention Policy to User Mailboxes
  2. On the Bulk Assign Retention Policy page, select your created retention policy from the drop-down list and click Save.
Select your created retention policy from the drop-down list

Hence the new Retention Policy is assigned to all the selected user mailboxes. To confirm, go to the Mailboxes page, select the mailbox, and click Edit and then on the Mailbox features option where you can confirm the assigned retention policy.

Confirm the assigned retention policy

We've now explored the process of configuring both the Office 365 Archive Policy and Deletion Policy. Please note that it may require up to 7 days for new retention policies to take effect across user mailboxes in Office 365. However, you can force this using the cmdlet: Start-ManagedFolderAssistant in Exchange Online PowerShell cmdlet.

To do this, execute the following command.

  1. Open your Windows PowerShell on your local system (run it as administrator).
  2. After opening, run the following command.

    $UserCredential = Get-Credential

    Open your Windows PowerShell on your local system
  3. Then a dialogue box named Windows PowerShell Credential Request gets opened. Type your Office 365 global admin account username and password and then click OK. Type your Office 365 global admin account username and password
  4. Execute the following command:

    Session = New-PSSession –ConfigurationName Microsoft.Exchange –ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential –Authentication Basic -AllowRedirection

    Then, run this command:

    Import-PSSession $Session

    Run the command To verify Exchange Online connection, run this command to get all mailboxes from your specified Office 365 account:

    Get-Mailbox

    Verify Exchange Online connection
    Now run:

    Get-mailbox -resultsize unlimited

    Next command
    Finally, run this command to complete the process:

    $Mailboxes.Identity | Start-ManagedFolderAssistant

    Complete the process

Users are equipped with a comprehensive manual outlining the steps to assign the Office 365 Archive Policy and Deletion Policy. Typically, it may require up to 7 days for these policies to become active. However, if an immediate application is needed, you can force the retention policy to take effect right away by initiating the Managed Folder Assistant using Windows PowerShell cmdlets within your Office 365 environment.

Backup Office 365 using professional tools

Office 365 is great, but its built-in saving options don’t cover everything. Imagine if you could only save some of your photos to a cloud, not all of them—that's how Office 365's saving features work. They're fine for a few things here and there, but for the whole data, you'll need more.

That's where specialized backup tools come in handy. These tools are like the protectors for your Office 365 data. They can save every single part of it: all your emails, the folders everyone in your office shares, and even those old emails you've tucked away into archives. And the best part? You get to choose how and where your data gets saved. We recommend going for the Kernel Office 365 Backup and Restore tool that supports all your Office 365 backup plans.

It's a really smart move to back up your data with these tools. They keep your important information secure. In the world of data, accidents can happen—emails get deleted, data gets lost. But with a complete backup, you can always get your data back. It's all about staying safe and prepared, making sure you never lose a byte of your valuable Office 365 data.

Conclusion

In Office 365, you have the power to set up your own archive and deletion rules that match your company’s specific needs. This makes managing your data easy. A global administrator can put these policies in place through the Exchange admin center or by using the Exchange Management Shell. It might seem a bit complex at first, but our guide surely fixes all your problems.

But, for the ultimate safety of your Office 365 data, there's something else you should consider: a professional Office 365 Backup and Restore tool. This isn't just another step—it's an essential layer of protection for your data. This utility guarantees that no matter what happens, your data is safe, secure, and recoverable. Investing in such a tool is a smart move for anyone serious about data security in Office 365.

FAQs

Q - What is the default policy for archive mailbox in Office 365?

A - By default, Office 365 has a 2-year move to archive policy for mailbox folders. This means that after 2 years, emails will be automatically moved to the archive mailbox (if the user has one).

Q - How do I assign a retention policy to my mailbox in Office 365?

A - To assign a retention policy to your mailbox in Office 365, you'll first need to navigate to the Recipients menu & select the Mailboxes option. Once you've found your User Mailbox, click on Mailbox features to access the Retention policy list. From there, you can choose the specific policy that you want to apply to your mailbox, & simply hit Save to finalize your selection.

Q - Do retention policies apply to archive mailboxes?

A - When implementing a retention policy in Exchange Online, it's important to note that it will also apply to any archive mailboxes that exist. This means that emails will be moved to the archive mailbox if it's enabled & the retention policy tag has been set for two years.

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