Update 6/11/2026: We modified the date of this change to October 1, 2026 based on customer feedback. Please use that extra time to remove your dependencies on EWS.
As part of our ongoing efforts to...
Updated Jun 11, 2026
Version 5.0
Blog Post
It looks like Microsoft has disabled EWS in many tenants for F and Kiosk licenses ahead of their announced date.
Greg Taylor - EXCHANGE
Microsoft
MicrosoftNo, we have not Gary. What makes you say that?
Greg Taylor - EXCHANGE I found out that the tenant set for EWS must be "true" and NOT "null" in order to access Kiosk license.
This doesn't line up with the official statement.
Can you please shade a bit of light on this?- Greg Taylor - EXCHANGE
Hey Nicco - that shouldn't be required. If you have been flipping the bit back and forth it can take up to 24 hours to take effect consistently, given 100's of 000's of servers in play. If you can confirm though you have waited, I'll take a look into it. Setting EWSEnabled to True at the tenant level, if you really want to use it though, is definitely what I'd advise.
Greg Taylor - EXCHANGE thanks for the prompt reply!
I've been working with a customer of mine who is extensively using Kiosk mailboxes to save costs. Since March their backup software stopped accessing those and it has been consistently getting the "403" error.
As soon as the tenant level setting for EWS was changed from "null" to "true" (or at least after a few hours), the software stopped receiving the errors and started again to pick up data.
I am also seeing this in my tenant. 8000+ F3 mailboxes now have EWS set to disabled. And I cannot change them back to EWSenabled $true.
Greg, why was this done early, instead of waiting until the actual deadline? This has broken backups from our third party backup provider as they thought they had until June before F3 EWS deprecation?
- Greg Taylor - EXCHANGE
Hey Dustin - it wasn't done early, nothing has changed. You can't set EWS to Enabled on an F3 license, but, it works anyway. That's the thing we're changing end of June. If EWS is enabled at the tenant level, (set it to True, you want to use EWS) then all F3 users can be accessed using EWS. Until end of June. If you are not seeing that, contact support. But please check the tenant setting, and if EWS actually works, not just looks at the per-user setting - it lies. For now.
Hello Greg thanks for the reply. I confirmed at the tenant level, EWSEnabled is already set to true via get-organizationconfig.
However we can no longer access any mailboxes that have an F3 license via EWS. The backup software is getting a HTTP 403 when connecting via EWS.EWS still works for our E3/E5 licensed mailboxes. Backups still are successful on those mailboxes.
Are you 100% sure this depreciation didn’t start earlier than expected?
