Oleksii Shevchenko
@shevsoftware.com
Independent consultant in Poland. I write about Exchange Online EWS retirement: two allow lists, usage-report limits, and dated evidence. I offer written EWS readiness audits. Sources and scope: shevsoftware.com
Microsoft will not overwrite a list an admin already configured. Generated lists still need review because infrequent apps may be omitted and unwanted apps included. Updated guide and source: www.shevsoftware.com/guide/
MSP guide to the Exchange Online EWS retirement — SHEV Software
Timeline, state matrix, tenant-specific EWS allow-list creation, usage-report limits, the full-replacement write trap and a multi-tenant checklist — sourced and dated.
www.shevsoftware.com
September 7, 2026 at 9:57 AM
Microsoft will not overwrite a list an admin already configured. Generated lists still need review because infrequent apps may be omitted and unwanted apps included. Updated guide and source: www.shevsoftware.com/guide/
Rollout starts tenant by tenant on 1 October. If EwsEnabled=true and no list exists, Microsoft creates one shortly before the new logic arrives, from the prior 60 days. If EwsEnabled=null, a list may appear only later in October before Microsoft sets EwsEnabled=false.
September 7, 2026 at 9:57 AM
Rollout starts tenant by tenant on 1 October. If EwsEnabled=true and no list exists, Microsoft creates one shortly before the new logic arrives, from the prior 60 days. If EwsEnabled=null, a list may appear only later in October before Microsoft sets EwsEnabled=false.
If EWSEnabled is unset (Null) today, Microsoft will set it to False for you during the staged rollout. Doing nothing is also a decision - it just gets made by someone else. What each combination means after October: www.shevsoftware.com/guide/
August 21, 2026 at 4:39 PM
If EWSEnabled is unset (Null) today, Microsoft will set it to False for you during the staged rollout. Doing nothing is also a decision - it just gets made by someone else. What each combination means after October: www.shevsoftware.com/guide/
One detail worth flagging from MC1446796: cross-tenant free/busy needs EwsEnabled=True on both sides until 1 April 2027, and it keeps working regardless of the App ID allow list. If the partner disables EWS early, you lose access to their data - they keep access to yours.
August 14, 2026 at 11:06 AM
One detail worth flagging from MC1446796: cross-tenant free/busy needs EwsEnabled=True on both sides until 1 April 2027, and it keeps working regardless of the App ID allow list. If the partner disables EWS early, you lose access to their data - they keep access to yours.