MC1227454 EWS begins being disabled October 1, 2026 · fully retired, including allow lists, April 1, 2027

EWS retirement: vendor status directory

Products that connect to Exchange Online through app registrations created in your tenant (most backup, migration, voicemail, and CRM-sync tools) won’t match a global App ID in any database — including ours. If the decoder shows an unidentified App ID with heavy EWS traffic, it is very likely one of these. Vendor-published status and remediation, with sources:

Vendor / productCategoryStatusWhat to doSource
Veeam Backup for Microsoft 365BackupVendor fix availableUpgrade to v8.5 and add the required Microsoft Graph permissions to your backup app registrations per KB4820/KB4873.Veeam KB4820
Veeam Data Cloud for Microsoft 365BackupVendor fix availableA Global Admin must reauthorize the Veeam Data Cloud app (Settings → Microsoft 365 → Reauthorize) so it gains the Graph permissions replacing EWS.Veeam KB4820
Mimecast Sync & Recover / Threat RemediationArchivingFix by deadlineMigrate to Mimecast’s Graph API server connector when it ships (target Aug–Sep 2026), per Mimecast’s Migrating Server Connectors guide.Mimecast KB
Mimecast Restore / Continuity / JournalingArchivingAction requiredBefore end of August 2026, add the Mimecast app IDs to your EWS allow list and set EWSEnabled=True so these services keep working through March 31, 2027 while Mimecast completes Graph migration.Mimecast KB
Cisco Unity Connection (Unified Messaging)VoicemailVendor fix availableUpgrade to Unity Connection 15 SU4 (15.0.1.14900-45) or later, which replaces EWS with Microsoft Graph for Microsoft 365 unified messaging.Cisco FN74365
Salesforce Einstein Activity Capture / InboxCRM syncFix by deadlineUpgrade the org’s Microsoft 365 connection from EWS to Microsoft Graph by August 3, 2026 (Salesforce/Microsoft recommended deadline) or sync stops when EWS is disabled.Salesforce release notes
Salesforce Lightning SyncCRM syncFix by deadlineLightning Sync has no Graph path — migrate to Einstein Activity Capture before August 2026, then ensure the EAC connection uses Microsoft Graph.Salesforce release notes
AvePoint Cloud Backup / Fly / OpusBackupVendor fix availableAvePoint is shipping its Graph transition in the Feb/Jun/Aug 2026 releases; most customers only need to consent to updated app permissions when prompted.AvePoint advisory
Commvault / Metallic Exchange Online backupBackupFix by deadlineCommvault’s Graph-based Exchange backup lands Summer 2026 (Release 11.44 LTS, SaaS and Software) — plan the update and keep EWS allow-listed until then.Commvault advisory
Quest On Demand MigrationMigrationAction requiredODM mailbox/public-folder migration still relies on EWS — keep EWS enabled at tenant level and allow-list the ODM app for the duration of migration projects.Quest KB4378864
CodeTwo Backup / Office 365 MigrationMigrationVendor fix availableCodeTwo migration and backup tools currently connect via EWS; Graph support is being added — keep EWS enabled for these tenant-registered apps until migration jobs finish or the Graph update ships.CodeTwo blog
Crestron Fusion room schedulingRoom bookingVendor fix availableCrestron Fusion supports Microsoft Graph for Exchange Online room calendars — reconfigure scheduling connections from EWS to a Graph app registration.Crestron docs
ResourceXpress (QED) room/desk bookingRoom bookingVendor fix availableIf your ResourceXpress server host is still outlook.office365.com/EWS/Exchange.asmx, switch the integration to graph.microsoft.com before October 1, 2026 or booking sync stops.ResourceXpress notice
Robin room bookingRoom bookingVendor fix availableRobin accounts created before September 2023 use EWS — run Robin’s self-service Microsoft Graph Migration Tool to move the Microsoft 365 integration to Graph.Robin support
UiPath Exchange Server activitiesAutomationAction requiredUiPath’s Exchange activities are EWS-based and in maintenance mode — rebuild affected workflows on the Microsoft 365 (Graph) activities/connector before October 2026.UiPath guide

Vendor missing, or status out of date?

We maintain this directory through the April 2027 retirement. Corrections and additions: appid@whatbreaksnext.com. Every entry cites the vendor’s own advisory — verify against your contract and versions before acting.