How to apply Outlook web app mailbox policies

An Outlook web app mailbox policy (previously known as an OWA mailbox policy) functions as a configuration template that determines which features are available to users when they access their email via the web. Rather than managing settings individually, administrators use these policies to enable or disable capabilities—such as text messaging, instant messaging, and file access—for specific users or groups. This ensures a consistent experience and efficient management of web-based email features across the organization.

For admins, managing these assignments manually for each user is inefficient. Without a streamlined method to assign Outlook mailbox policies to user accounts, ensuring consistency across departments becomes difficult. This article explains how to assign Outlook web app mailbox policies to users in Exchange Online using the Exchange admin center and Exchange Online PowerShell.

Method 1: How to apply Outlook policies using the Exchange admin center

Prerequisites

You need the Exchange Administrator role for the account you use to sign in to the Exchange admin center.

Steps

1. Log in to the Exchange admin center.
2. Navigate to Recipients > Mailboxes and click a mailbox.
3. Click Manage email apps settings under Email apps & mobile devices.
4. Type the name of the Outlook web app mailbox policy you want to apply and click it. To remove an existing Outlook policy, click the X button next to it.
5. Click Save.

A limitation to consider

The Exchange admin center only allows you to edit the Outlook web app mailbox policy of one mailbox at a time. You have to use Exchange Online PowerShell to apply an Outlook web app mailbox policy to multiple users at once.

Method 2: How to apply Outlook policies using Exchange Online PowerShell (Set-CASMailbox)

Prerequisites

Before using Exchange Online PowerShell, please verify that:

• The Exchange Administrator role is applied to the account you use to sign in to Exchange Online PowerShell.
• You are connected to the Exchange Online PowerShell module.
  1. To check if the Exchange Online PowerShell module is installed, use this script:
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                                             Get-Module -ListAvailable ExchangeOnlineManagement
                                         

  2. If the script does not return a value, you will have to install the module. To install the Exchange Online PowerShell module, execute this script:
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                                             Install-Module ExchangeOnlineManagement -Scope CurrentUser
                                         

  3. To connect to Exchange Online PowerShell, run this script:
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                                             Connect-ExchangeOnline
                                         

Using Set-CASMailbox to assign Outlook web app mailbox policies

The Set-CASMailbox cmdlet can be used to enable or disable certain Exchange Online features that provide users with different ways to access their mailboxes.

Use the Set-CASMailbox cmdlet to assign a specific Outlook web app mailbox policy to a user:

Set-CASMailbox -Identity user@domain.com -OwaMailboxPolicy "PolicyName"

Scenario: Assign a restrictive Outlook web app mailbox policy in bulk to a department

An IT administrator needs to apply a restrictive Outlook policy to all users in the Interns department to disable instant messaging and file sharing.

They use the following script to find the users in the department and assign the Outlook web app mailbox policy to user mailboxes in the Interns department in bulk:

$Users = Get-User -ResultSize Unlimited -Filter "Department -eq 'Interns'"
$Users | ForEach-Object {
    Set-CASMailbox -Identity $_.UserPrincipalName -OwaMailboxPolicy "RestrictedOWAPolicy"
}

Supported parameters

The following table contains parameters relevant to managing Outlook policies via Exchange Online PowerShell:

Validation: How to ensure your Outlook web app mailbox policies are applied

Use the Get-EXOCASMailbox cmdlet to verify which Outlook web app mailbox policy is assigned to a user:

Get-EXOCASMailbox -Identity <UserPrincipalName> | Select-Object Identity, OWAMailboxPolicy
                            

You can also check the email apps settings of each mailbox in Exchange Online for the Outlook web app mailbox policy applied to it.

Manage your Exchange Online protocols and more

While native admin centers and Graph PowerShell scripting can help you assign Outlook web app mailbox policies to your mailboxes, you either need a great deal of patience to make changes to mailboxes one by one or extensive knowledge of PowerShell scripting to carry out your complex and bulk operations. This is where ManageEngine M365 Manager Plus helps you simplify your Microsoft 365 administration.

M365 Manager Plus is a comprehensive administration and security solution for Microsoft 365. It is used for reporting on, managing, monitoring, auditing, and creating alerts for critical activities in your Microsoft 365 environment.

M365 Manager Plus' mailbox management capabilities help you view, monitor, and modify Exchange Online mailbox properties like the mailbox quotas, archive status, and inbox rules. You can carry out complex tasks like configuring retention policies, converting mailboxes, and more with just a series of clicks. Instead of juggling scripts or exporting raw data for manual filtering, you can use M365 Manager Plus' ready-to-use reports and easy scheduling.

Important tips

Frequently asked questions

Set-CASMailbox -Identity user@domain.com -OwaMailboxPolicy "OwaMailboxPolicy-Default"

Set-CASMailbox -Identity user@domain.com -OwaEnabled $false.