Microsoft is retiring Exchange Web Services (EWS) in Exchange Online. This is a Microsoft platform change, not a PoliteMail change, but it affects how PoliteMail expands distribution lists and resolves recipients.
| If PoliteMail is already configured for Microsoft Graph | If you rely on EWS to expand Exchange Online Dynamic Distribution Lists (DDLs) | If you have On-Premises Exchange |
|---|---|---|
You are largely unaffected, unless you send to Exchange Dynamic Distribution Lists, which is not handled by Graph. | Action is needed! Microsoft Graph does not provide equivalent capability; those lists need to be migrated to Entra/M365 equivalents or handled another way. | You are not affected. This retirement applies only to Exchange Online. |
Microsoft’s official timeline
| Date | Event |
|---|---|
October 1, 2026 | Retirement enforcement begins. Tenants with EWSEnabled unset (Null) are moved to False on a phased, tenant-by-tenant basis. EWSEnabled=True without an allow list no longer permits unrestricted EWS access; all EWS traffic except cross-tenant organization relationships is blocked. Until April 2027 an admin can still set EWSEnabled=True and add an allow list to restore access. |
April 1, 2027 | Full retirement. EWS in Exchange Online is permanently disabled; setting EWSEnabled=True no longer restores access. |
Microsoft had an end-of-August 2026 exclusion window that is now closed. Tenants that did not configure EWSEnabled=True with an allow list should assume they are in the phased October 1 disablement wave. Configuring the allow list now still works: it either prevents the switch or lets you restore access quickly after it, but a short outage is possible.
Frequently Asked Questions
Is EWS going away in October 2026? No. October 1, 2026 is when Microsoft begins turning it off tenant by tenant and when unrestricted access ends. The permanent shutdown is April 1, 2027.
We already use Graph. Do we need to do anything? Only if you send to Exchange Dynamic Distribution Lists. Everything else PoliteMail expands is covered by Graph.
Will Graph ever support DDLs? Not Graph itself. Microsoft's replacement is the Exchange Online Admin API DynamicDistributionGroupMember endpoint, currently in preview and not available in all organizations. PoliteMail does not use it yet. Do not build your plan on it.
What happens if we do nothing? Once your tenant is disabled, users sending to affected lists will see expansion failures or wildly undercounted recipients. Sends to static groups, security groups, M365 groups, and Entra dynamic groups continue to work normally.
Sources
- Deprecation of Exchange Web Services in Exchange Online — Microsoft Learn
- Retirement of Exchange Web Services in Exchange Online — Microsoft 365 Developer Blog
- Migrate EWS apps to Microsoft Graph — Microsoft Learn
- EWS to Microsoft Graph API mappings — Microsoft Learn
- Exchange Online EWS, Your Time is Almost Up — Exchange Team Blog
- Set-OrganizationConfig (EwsEnabled, EwsAllowedAppIDs) — Microsoft Learn
- DynamicDistributionGroupMember endpoint, Exchange Online Admin API (preview) — Microsoft Learn
- PoliteMail Graph permissions
- PoliteMail: Setting up and Configuring the EWS Client
- PoliteMail: Using EWS Cache for Fast Expand
