Microsoft has officially announced the retirement of Exchange Web Services (EWS) for Exchange Online, with the service being fully disabled on October 1, 2026. This change has important implications for organizations that rely on third-party applications accessing Public Folder data, especially contacts and calendars.
WHAT IS CHANGING?
EWS has long been used by third-party applications and custom integrations to access Exchange Online data such as contacts, calendars, mailboxes, and Public Folders. As part of Microsoft’s broader security and modernization initiative, EWS will be disabled for all Exchange Online tenants on October 1, 2026. After this date, any EWS-based access will stop working.
Important: This change applies only to Exchange Online. Exchange Server on-premises is not affected.
IMPACT ON PUBLIC FOLDERS
One of the most significant consequences of the EWS retirement is its effect on Public Folders. Many third-party tools rely on EWS to read or synchronize Public Folder contacts and calendars. When EWS is disabled:
- Third-party applications will lose all EWS-based access to Public Folders
• Public Folder data will no longer be accessible forsyncing or integration
• Existing workflows built around Public Folder contacts and calendars may break
Microsoft Graph currently offers limited support for Public Folder scenarios, which makes a direct replacement for many EWS-based Public Folder integrations impractical.
WHO SHOULD BE PLANNING NOW?
You should start planning immediately if:
- Your organization uses third-party apps that read from or write to Public Folder contacts or calendars
- Public Folders are part of your CRM, address book, or scheduling workflows
- You depend on bi-directional sync between Public Folders and other systems
Although October 2026 may seem far away, migrating shared data structures—especially those tied to business processes—takes time, testing, and coordination.
RECOMMENDED MIGRATION OPTIONS
Shared Mailboxes (Recommended)
A shared mailbox is often the best replacement for Public Folders when working with contacts and calendars. Shared mailboxes are fully supported by Microsoft Graph, ideal for shared contact lists and calendars, compatible with modern authentication, and supported by most third-party tools.
CRM or Centralized Contact Repositories
In some cases, organizations may choose to migrate Public Folder data into a CRM system, or another centralized contact repository, especially when Public Folder contacts are customer- or partner-facing.
HOW CIRAHUB CAN HELP
CiraHub is designed to help organizations adapt to the EWS retirement by providing flexible, multi-way contact and calendar synchronization.
With CiraHub, you can:
- Migrate Public Folder contacts and calendars to a shared mailbox
- Keep data synchronized during and after migration
- Replace Public Folder dependencies with modern, supported data sources
- Integrate shared contacts and calendars with popular CRM platforms
SUPPORTED CRM CONNECTORS
CiraHub supports synchronization with the following CRMs:
- Salesforce
- HubSpot
- ActiveCampaign
- Pipedrive
- Zoho CRM
- Procore
- DealCloud
- QuickBooks
- Clio
- Workday
- Everbridge
- Copper
NEXT STEPS
If your organization still relies on Public Folder data for third-party integrations, now is the time to inventory applications using EWS, identify Public Folder dependencies, choose a modern replacement, and plan migration before October 2026.
