Microsoft Changes to Exchange Web Services (EWS): What Exclaimer users need to know

Microsoft has announced that it will begin retiring Exchange Web Services (EWS) 

in Exchange Online from October 2026, with the service being fully disabled by April 2027. This change affects one specific Exclaimer feature called Sent Items Update.

For most users, there will be very little noticeable impact. Your email signatures will continue to work as normal and there will be no interruption to the delivery of professionally branded emails.

What is the Sent Items Update?

Sent Items Update is an optional Exclaimer feature that writes a copy of sent emails back into a user’s mailbox with the email signature already applied. This allows users to see the final version of the email, including the signature, within their Sent Items folder.

What is changing?

The current Sent Items Update functionality relied on Microsoft’s Exchange Web Services (EWS). As Microsoft retires EWS, this feature will no longer be able to operating using its existing methods.

Will my email signatures stop working?

No.

Exclaimer has confirmed that both server-side and client-side signature deployment are unaffected by the retirement of EWS. Your recipients will continue to receive emails with the correct signatures applied.

What will users notice?

The main change is that emails stored in the sender’s Sent Items may not show the final email signature, even though the recipient receives the correctly branded email. For many businesses, this will have little day-to-day impact, but it is worth making users aware of the change so they understand why there may be a difference between what they see in Sent Items and what recipients receive.

What’s do I need to do?

For most businesses, the answer is very little. The retirement of EWS only affects Exclaimer’s Sent Items Update feature. Your email signatures will continue to be applied to outgoing emails as normal, and there is no disruption to email delivery.

• If you have an internal IT team: We recommend making your IT team aware of this change so they understand the impact on your environment. Your team should:
  • Review whether your business uses Exclaimer’s Sent Items Update feature.
  • Inform users that emails in their Sent Items folder may no longer display the final signature.
  • Monitor communications from Exclaimer regarding its replacement solution based on Microsoft’s Graph API.
• If you don’t have dedicated IT support: There’s no immediate action required. Your email signatures will continue to work as expected. If you’re unsure whether this affects your business, contact Apex and we’ll be happy to advise.
• If you work with an MSP or IT Partner: Forward this update to your IT provider if they haven’t contacted you about it already and ask them to confirm whether your Exclaimer deployment uses Sent Items Update. Your provider can review your setup, explain any impact to your users and keep you informed of any future updates from Exclaimer as its replacement service becomes available.