CodeTwo products vs EWS retirement in Exchange Online

Microsoft will begin disabling Exchange Web Services (EWS) in Exchange Online starting October 2026. From that point, applications that rely on EWS will 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 currently use EWS, and what limitations may apply until Microsoft confirms support for all EWS-based scenarios in Graph.

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

If you’re using CodeTwo Email Signatures 365 with Sent Items Update (SIU), make sure you’re using the new Graph version of SIU. If your tenant still uses the legacy EWS version, you need to reconfigure SIU to switch to Microsoft Graph. See this guide for instructions

If you’re using CodeTwo migration or backup software, or the Sent Items Update feature in CodeTwo Email Signatures On-prem in a hybrid environment, make sure EWS is explicitly enabled in your Microsoft 365 tenant and the required CodeTwo app IDs are added to the AppID Allow List (EWSAllowedAppIDs), so that your CodeTwo products continue to work. See this section or read on for more details.

We’re already working on Microsoft Graph support to ensure uninterrupted operation of all our software after EWS retirement. We will notify our customers (via email) and update this article as soon as Microsoft Graph support becomes available across our products. Our goal is to make this transition as smooth as possible and keep you informed every step of the way.

Which CodeTwo products use EWS today?

Some CodeTwo products for Microsoft 365 still rely on EWS to connect to Exchange Online and provide certain features.

Use the links below to learn how EWS retirement affects specific CodeTwo products:

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

While the retirement of EWS has been known for some time, transitioning from EWS to Microsoft Graph depends on Microsoft providing equivalent Graph functionality. Many of the Graph API capabilities required to support existing EWS-based scenarios have only recently become available or are still under development. We have been working closely with Microsoft and gradually transitioning affected CodeTwo products and features as the necessary Graph components become available. Moving to Microsoft Graph will also improve security, reliability, and future compatibility.

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 uses EWS is Sent Items Update (SIU), 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 that use the EWS version of SIU need to reconfigure their app, as described here. We’ve already notified these customers and will continue to remind them about the required reconfiguration.

In CodeTwo Email Signatures On-prem, we’re currently migrating SIU to Microsoft Graph. We will update this article and notify customers when the new version of SIU becomes available.

Important: For CodeTwo Email Signatures On-prem, the above applies only to hybrid Exchange environments. If you’re using the product with a stand-alone on-premises Exchange Server, Sent Items Update will continue to use EWS.

EWS retirement vs CodeTwo migration tools

Related products: CodeTwo Office 365 Migration, CodeTwo Exchange Migration

We’re working closely with Microsoft to ensure the Graph API supports all migration scenarios currently available through EWS. However, at the time of writing, Microsoft Graph support for the following resources is at different stages:

• Archive mailboxes – support planned for Q4 2026.
• Public folders – support planned for Q4 2026.
• IMAP servers (access to emails) – Microsoft has not yet confirmed full support.

As a result, migrations involving archive mailboxes and public folders to or from Microsoft 365, as well as migrations from IMAP servers may be limited or unavailable after April 2027. We’re monitoring these developments and will update this article as soon as Microsoft provides more information.

If you plan to migrate archive mailboxes, public folders, or emails from IMAP servers such as Google Workspace, Zimbra, and other platforms, consider completing those migrations before April 2027. See also: EWS retirement is near – migrate public folders with CodeTwo

Important: Archive mailbox and public folder migrations between on-premises Exchange environments will not be affected by EWS retirement.

EWS retirement vs CodeTwo backup software

Related product: CodeTwo Backup for Office 365

CodeTwo backup software currently relies on EWS to connect to Exchange Online. We’re working on support for the Graph API to ensure backup and restore operations continue to work after EWS retirement.

However, at the time of writing, Microsoft Graph support for the following resources is at different stages:

• Archive mailboxes – support planned for Q4 2026.
• Public folders – support planned for Q4 2026.
• Microsoft 365 group mailboxes – Microsoft has not yet confirmed full support.

As a result, backup and restore operations involving these resources may be limited or unavailable after April 2027. We’re monitoring these developments and will update this article as soon as more information becomes available.

How to ensure CodeTwo software works before Graph versions are released

Microsoft will begin disabling EWS tenant by tenant starting in October 2026. However, we have already observed cases where EWS access was disabled in some tenants as part of Microsoft’s scream tests.

Until Graph-enabled versions of the affected CodeTwo products are released, make sure EWS remains enabled in your Microsoft 365 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). Starting October 1, 2026, Microsoft will begin blocking EWS access for apps in tenants where the list is empty.

To 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. 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.