CodeTwo products vs EWS retirement in Exchange Online

Microsoft begins globally disabling Exchange Web Services (EWS) in Exchange Online on October 1, 2026. From that point, applications that rely on EWS may stop working unless Microsoft 365 admins manually enable EWS in their tenants and define an AppID Allow List. The complete shutdown of EWS is planned for April 2027.

Microsoft’s recommended successor to EWS for accessing Exchange Online data and other Microsoft 365 services is Microsoft Graph – a modern API designed for growing cloud environments. EWS will continue to be fully supported in on-premises Exchange Server environments.

Read on to learn if you need to take any action, which CodeTwo products still use EWS, and what limitations may apply until Microsoft adds support for all EWS-based scenarios in Graph.

Do CodeTwo customers or end users need to do anything now?

Some CodeTwo products for Microsoft 365 relied on EWS to connect to Exchange Online and provide certain features. We have been working closely with Microsoft and have gradually migrated affected CodeTwo products and features to Microsoft Graph as the necessary Graph components became available. Moving to Microsoft Graph also provides improved security, reliability, and future compatibility.

Use the links below to learn if you need to do anything regarding your CodeTwo product:

• The Sent Items Update feature in CodeTwo email signature software
• CodeTwo migration software
• CodeTwo backup software

EWS retirement vs CodeTwo email signature software

Related products: CodeTwo Email Signatures 365, CodeTwo Email Signatures On-prem (hybrid deployments only)

The retirement of Exchange Web Services doesn’t affect adding CodeTwo signatures to emails.

The only feature in our email signature solutions that used EWS is Sent Items Update (SIU), which is responsible for updating emails in the Sent Items folder with the signature that was added in the cloud (after the email was sent).

In CodeTwo Email Signatures 365, we’ve already migrated the Sent Items Update app to Microsoft Graph. New customers get the Graph version by default, and customers who use the EWS version of SIU need to reconfigure it, as described here. We’ve already notified these customers and will continue to remind them about the required reconfiguration.

Similarly, we’ve released a new version of CodeTwo Email Signatures On-prem that includes the Graph-compatible SIU. Customers with hybrid environments (with both Exchange Online and on-premises Exchange mailboxes) that use SIU need to update the program and reconfigure SIU as described here to continue seeing signatures in Sent Items.

Important: If you’re using the product with a stand-alone on-premises Exchange Server, Sent Items Update will continue to use EWS, so there’s no need to reconfigure SIU.

EWS retirement vs CodeTwo migration tools

Related products: CodeTwo Office 365 Migration, CodeTwo Exchange Migration

We released new versions of CodeTwo migration software that use Microsoft Graph instead of EWS to connect to Microsoft 365 (Exchange Online).

At the time of writing, Microsoft Graph support for the following resources is planned for Q4 2026:

• Archive mailboxes
• IMAP servers (access to emails)

As a result, migrations involving archive mailboxes to or from Microsoft 365, as well as migrations from IMAP servers, are not yet supported in the new Graph versions. We continue to work closely with Microsoft to restore support for these migration scenarios in future releases.

Update (October 27, 2026): Microsoft disabled support for public folder migrations in the Microsoft Graph API to address some issues. The latest versions of CodeTwo migration software were released with support for public folder migrations, but due to this change, the feature is temporarily unavailable. Microsoft plans to restore this functionality by the end of December 2026.

Important: If you are currently migrating using a version of CodeTwo migration software prior to 3.3.x, finish your migration jobs before installing the Graph version. Otherwise, you’ll need to configure your jobs again and start the migration process from the start, which might create duplicate items. You can continue using the EWS version until April 1, 2027, when Microsoft plans to permanently block EWS in Exchange Online. Until then, make sure EWS is enabled in your tenant and the CodeTwo migration app is added to your EWSAllowedAppIDs list, as described in this section.

EWS retirement vs CodeTwo backup software

Related product: CodeTwo Backup for Office 365

The new, Microsoft Graph-compatible version of CodeTwo Backup for Office 365 is now available and completely free to use!

If you use CodeTwo Backup to back up or restore Exchange Online (Microsoft 365) data, we recommend updating to the new version now rather than waiting for Microsoft to retire EWS.

To update, download the latest version and install it on top of your current version. Your settings and jobs will be retained, but you’ll need to reconfigure your existing Exchange Online connections to use Microsoft Graph. See how to do that

Important: Support for backing up and restoring Exchange Online archive mailboxes has been temporarily removed because the necessary APIs are not yet available from Microsoft.

The new version of the program also no longer supports on-premises Exchange environments. If you back up on-premises Exchange data (mailboxes and public folders), stay on version 2.5.x.

How to continue using EWS-compatible software in Microsoft 365

Microsoft began disabling EWS tenant by tenant on October 1, 2026.

To continue using the previous version of CodeTwo migration software that still uses EWS to connect to Microsoft 365, make sure EWS remains enabled in your tenant. Currently, PowerShell is the only way to view and modify your organization’s EWS configuration.

Check whether EWS is enabled

1. Connect to your Exchange Online organization with PowerShell (see this article for instructions).
2. Use the following cmdlet to check if EWS is enabled organization-wide:

Get-OrganizationConfig | select EWSEnabled

If the result is False or you don’t get any value (Null), as shown below, continue to the next section.

Important: The Null value is treated as True until September 2026. Starting October 1, 2026, Microsoft will begin changing the Null value to False as part of the phased EWS retirement rollout. So, to avoid disruptions, set the value to True (enable EWS).

Enable EWS for the organization

1. To enable EWS across your organization, run the following cmdlet (you need to be your organization’s Microsoft 365 global admin or Exchange admin to be able to do this):

Set-OrganizationConfig -EwsEnabled:$true

2. To verify the configuration, run the following command again:

Get-OrganizationConfig | select EWSEnabled

The result should now be as shown below:

Allowing CodeTwo apps to use EWS

You can control which apps in your Microsoft 365 tenant can continue using EWS by configuring an AppID Allow List (the EWSAllowedAppIDs setting).

Before you create such a list, first enable EWS for your organization, then use the script below to add the IDs of CodeTwo apps you want to continue using EWS.

Important: If EWS is enabled but the EWSAllowedAppIDs list is empty, all EWS access will be blocked.

The script adds new app IDs to the list without overwriting any existing entries:

$AllowedAppIDs = (Get-OrganizationConfig -RetrieveEwsOperationAccessPolicy | select EwsAllowedAppIDs) # Gets the list of currently allowed app IDs and stores it in a variable.

$AllowedAppIDs # (Optional) Returns the list retrieved in the previous step.

$NewAppID = "3153c72b-35a8-465b-84d8-dfb56651836a" # Saves the app IDs you want to add to the allowed list in a variable. Replace the sample ID with the IDs of the CodeTwo apps you want to allow to use EWS (separate multiple IDs with commas).

if ($AllowedAppIDs) {$UpdatedList = $AllowedAppIDs.EwsAllowedAppIDs + "," + $NewAppID} else {$UpdatedList=$NewAppID} # Checks if the -EWSAllowedAppIDs parameter is already populated and creates a list ($UpdatedList) that will be used to update your organization settings. Currently, using EWSAllowedAppIDs overwrites existing values, so this step ensures that any app IDs already included in the list will not be overwritten.

$UpdatedList # (Optional) Returns the updated list of allowed app IDs.

Set-OrganizationConfig -EwsAllowedAppIDs $UpdatedList # Updates the list of allowed app IDs.

Keep in mind that changes to the EWSAllowedAppIDs list can take up to 24 hours to propagate. If you don’t know where to find the IDs of the CodeTwo apps in your tenant, see this article.

Irrespective of these settings, EWS access will be permanently blocked in Exchange Online on April 1, 2027.