Salesforce (Einstein Activity Capture, Lightning Sync): ready for the EWS shutdown?

Short answer: Einstein Activity Capture and the Outlook integration use Microsoft Graph. Lightning Sync for Microsoft Exchange uses EWS and retires in April 2027 with no Graph version: move Lightning Sync users to Einstein Activity Capture or the Outlook integration before then.

⚠ Depends on the product or version · vendor statements checked 26 Oct 2026

Deadline: Exchange Online blocks EWS by default from October 2026 (tenants are switched to EwsEnabled False, rollout to late April 2027) and turns it off for good on 1 April 2027, with no exceptions. Exchange Server on-premises is not affected.

Status

EAC on Graph (Spring '26); Lightning Sync retires April 2027, no Graph version. Source is a secondary summary of Salesforce help; confirm in Salesforce Help (sales.eac_ews_graph) for your org.

This vendor registers its own app in each tenant, so the app ID is yours. Find it in the EWS usage report, or run the free script with -ResolveNames.

What to do

  1. List the users and configurations on Lightning Sync in Salesforce Setup.
  2. Move them to Einstein Activity Capture or the Outlook integration.
  3. Keep the Salesforce EWS app on the allow list only until the last Lightning Sync user is moved.

More than one app? Run the free read-only script: it names every app still calling EWS in your tenant.

Allow-list it safely

Setting EwsAllowedAppIDs replaces the whole list, so adding one ID on its own removes every other app. Read the current list first, then write the merged list:

Get-OrganizationConfig -RetrieveEwsOperationAccessPolicy | Format-List EwsEnabled,EwsAllowedAppIDs
Set-OrganizationConfig -EwsEnabled $true -EwsAllowedAppIDs "<current IDs>,<new ID>"

Changes to the list take up to 24 hours. A blocked call returns HTTP 403 with the header X-EWS-Policy-Reason. The free script prints the merged command for every app in use (it never runs it).

Sources

MSP or IT partner? The M365 Readiness Pack runs this EWS check, the SMTP AUTH check and SPF/DKIM/DMARC for every domain once per client tenant, and writes a client-ready report with your logo, next steps and an email to send the client. Read-only, works with GDAP.

See the pack (from $49)
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