๐ Secure Bits ๐ก
๐๐
๐ฐ๐ต๐ฎ๐ป๐ด๐ฒ ๐ช๐ฒ๐ฏ ๐ฆ๐ฒ๐ฟ๐๐ถ๐ฐ๐ฒ๐ (๐๐ช๐ฆ) ๐ถ๐ป ๐๐
๐ฐ๐ต๐ฎ๐ป๐ด๐ฒ ๐ข๐ป๐น๐ถ๐ป๐ฒ ๐ถ๐ ๐ผ๐ณ๐ณ๐ถ๐ฐ๐ถ๐ฎ๐น๐น๐ ๐ด๐ผ๐ถ๐ป๐ด ๐ฎ๐๐ฎ๐.
Microsoft will start disabling EWS in Exchange Online from October 1, 2026, with ๐ณ๐๐น๐น ๐ฎ๐ป๐ฑ ๐ฝ๐ฒ๐ฟ๐บ๐ฎ๐ป๐ฒ๐ป๐ ๐ฟ๐ฒ๐๐ถ๐ฟ๐ฒ๐บ๐ฒ๐ป๐ ๐ผ๐ป ๐๐ฝ๐ฟ๐ถ๐น ๐ญ, ๐ฎ๐ฌ๐ฎ๐ณ.
If any of your apps still rely on EWS, they ๐ค๐๐๐ break unless you act.
This often goes unnoticed because EWS is mostly used by background services, not end users โ until workflows suddenly stop.
๐ค ๐ช๐ต๐ ๐๐ต๐ถ๐ ๐บ๐ฎ๐๐๐ฒ๐ฟ๐
EWS is still widely used for mailbox, calendar, and service-to-service integrations.
When it breaks, the impact is operational and visible โ missing emails, failed automations, broken syncs โ but troubleshooting often starts in the wrong place.
Migration is rarely a checkbox. It usually requires application changes and testing.
๐ง ๐ง๐ผ ๐ด๐ถ๐๐ฒ ๐๐ผ๐ ๐บ๐ผ๐ฟ๐ฒ ๐ฐ๐ผ๐ป๐๐ฒ๐
๐
Microsoft is enforcing the long-announced shift from legacy Exchange APIs to Microsoft Graph.
– ๐ October 1, 2026 – EWS will be blocked by default unless explicitly allowed by tenant admins, they can re-enable this setting temporarily
– ๐ April 1, 2027 – EWS access in Exchange Online will be permanently removed – no re-enablement, no exceptions
– on-premise Exchange Server is not affected, this change applies only to Exchange Online
๐ ๏ธ ๐๐ฑ๐ฒ๐ป๐๐ถ๐ณ๐ ๐๐ช๐ฆ ๐๐๐ฎ๐ด๐ฒ ๐ป๐ผ๐
Use the built-in report to see all apps and identities using EWS in your tenant:
– Microsoft 365 admin center โ ๐ฅ๐ฒ๐ฝ๐ผ๐ฟ๐๐ โ ๐จ๐๐ฎ๐ด๐ฒ โ ๐๐
๐ฐ๐ต๐ฎ๐ป๐ด๐ฒ โ ๐๐ช๐ฆ ๐๐๐ฎ๐ด๐ฒ
๐ ๏ธ ๐ฃ๐น๐ฎ๐ป ๐บ๐ถ๐ด๐ฟ๐ฎ๐๐ถ๐ผ๐ป ๐๐ผ ๐ ๐ถ๐ฐ๐ฟ๐ผ๐๐ผ๐ณ๐ ๐๐ฟ๐ฎ๐ฝ๐ต
Microsoft Graph provides near-complete API parity, but migration usually involves:
– Code changes
– Permission model updates
– Regression testing
๐ก๏ธ ๐จ๐๐ฒ ๐๐ต๐ถ๐ ๐ฎ๐ ๐ฎ ๐๐ฒ๐บ๐ฝ๐ผ๐ฟ๐ฎ๐ฟ๐ ๐๐ฎ๐ณ๐ฒ๐๐ ๐ป๐ฒ๐
If EWS is still required after October 2026:
– Configure the AllowList
– Explicitly set ๐๐๐๐๐ฏ๐ข๐ฃ๐ญ๐ฆ๐ฅ = ๐๐ณ๐ถ๐ฆ
– Treat this as a short-term exception, not a long-term design
โ ๏ธ ๐๐บ๐ฝ๐ผ๐ฟ๐๐ฎ๐ป๐
Microsoft may run temporary โscream testsโ before October 2026 to surface hidden dependencies.
If something suddenly breaks during those tests โ thatโs your warning sign.
Assume EWS exists somewhere in your tenant unless youโve proven otherwise.
The earlier you identify and migrate dependencies, the cheaper and calmer this transition will be.
๐ฌ ๐ค๐๐ฒ๐๐๐ถ๐ผ๐ป ๐ณ๐ผ๐ฟ ๐ฎ๐ฑ๐บ๐ถ๐ป๐
Do you know exactly which apps in your environment still rely on EWS โ or would this retirement catch you by surprise?
๐๐ถ๐ต๐ฉ๐ฐ๐ณ ๐ฐ๐ง ๐ต๐ฉ๐ฆ ๐ฑ๐ฐ๐ด๐ต:
Martin Strnad
