Update 3/31/2026: This change has now been fully rolled out. If your EWS applications have access problems, please verify your tenant and mailbox level EWS settings.
In our ongoing commitment to en...
Updated Apr 01, 2026
Version 5.0
Blog Post
As per the below statement by MS, if EWS flag is empty then there is no impact, so we should not worry once MS rolled out the CHG starting Apr 2025, right?
""If the EWSEnabled flag is empty (the default), or set to True – this change won’t affect you, but we still advise you read the per-user settings information below to make sure it matches your expected settings.""
Yes, you are right EWS is enabled default for all the mailboxes but I dont see any way to determine if they actually need EWS.
I am sure application is using EWS , would EWS using application would impact or not.?
Nino_Bilic
Microsoft
MicrosoftReality of the situation is that today - many applications (Outlook included) still use EWS. This whole blog post is targeted to customers who have already started setting EWS to blocked (for reasons that are related to their business). Everyone (Microsoft included) will need to update their applications to stop using EWS before the 2026 deadline but indeed today - blocking EWS would likely break all kinds of stuff for most customers.
We are working on EWS usage reporting (more to follow relatively soon).