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How to enable EWS at the Exchange Online user (mailbox) level

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Introduction

Starting in April 2025, Microsoft is changing how EWS access is managed in Exchange Online. To use EWS, it must be enabled at both the organization (tenant) and user (mailbox) levels. For details on the changes and how to check if your users are affected, see EWS access control changes in Exchange Online.

To ensure Revenue Grid solutions continue to function without interruption, Exchange Online administrators must verify that EWS is enabled at both the organization (tenant) and user (mailbox) levels for users who connect via EWS.

This article provides step-by-step instructions for activating EWS at the user (mailbox) level in Exchange Online. If you have not yet activated EWS at the organization level, see How to enable EWS at the Exchange Online organization (tenant) level.

Configure EWS at the Exchange Online user level

Exchange Online administrators can enable EWS for users individually or in bulk.

Activate EWS for a specific user

  1. Connect to Exchange Online PowerShell:

    Connect-ExchangeOnline -UserPrincipalName admin@yourdomain.com

  2. Activate EWS for the user:

    Set-CASMailbox -Identity user@yourdomain.com -EwsEnabled $true

  3. Verify the change:

    Get-CASMailbox -Identity user@yourdomain.com | Select EwsEnabled

If the output is true, EWS is activated.

Allow EWS for users in a specific group

If you need to enable EWS for multiple users based on specific criteria, such as department or role, you can filter them using relevant attributes like Department or Title.

  1. Connect to Exchange Online PowerShell:

    Connect-ExchangeOnline -UserPrincipalName admin@yourdomain.com

  2. Allow EWS for users in the selected group:

    Get-CASMailbox -ResultSize Unlimited | 
    Where-Object {$_.Department -eq "Sales" -and $_.EwsEnabled -ne $true} | 
    Set-CASMailbox -EwsEnabled $true

  3. Verify the changes:

    Get-CASMailbox -ResultSize Unlimited | 
    Where-Object { $_.Department -eq "Sales" } | 
    Select DisplayName, UserPrincipalName, EwsEnabled

If the output is true, EWS is allowed for the listed users.

Enable EWS for users from a CSV file

If you need to activate EWS for a large number of users, you can upload a CSV file containing their email addresses and apply the change in bulk.

  1. Create a CSV file (e.g., users.csv) with the following format:

    UserPrincipalName
[email protected]
[email protected]

  2. Connect to Exchange Online PowerShell:

    Connect-ExchangeOnline -UserPrincipalName admin@yourdomain.com

  3. Run the following PowerShell script to enable EWS for all users in the CSV file:

    $users = Import-Csv -Path "C:\Path\To\users.csv"
$users | ForEach-Object { 
    Set-CASMailbox -Identity $_.UserPrincipalName -EwsEnabled $true 
}

  4. Verify the changes:

    $users = Import-Csv -Path "C:\Path\To\users.csv"
$users | ForEach-Object { 
    Get-CASMailbox -Identity $_.UserPrincipalName | 
    Select DisplayName, UserPrincipalName, EwsEnabled 
}

If the output is true, EWS is enabled for the listed users.

See also