Keep Dynamics 365 on-premise in sync with Exchange Online.
Microsoft is removing Exchange Web Services from Exchange Online, and server-side sync for Dynamics 365 on-premise stops with it. Prism Email Router replaces that sync, using the Microsoft Graph API.
Server-side sync is being switched off.
Dynamics 365 on-premise uses Exchange Web Services to synchronise with Exchange Online. Microsoft is removing Exchange Web Services from Exchange Online, starting in October 2026 and finishing on 1 April 2027. When it has gone, server-side sync no longer works.
Microsoft's guidance is to move to Dynamics 365 Online. If you need to stay on-premise for now, Prism Email Router keeps your email and activities synchronising.
The dates and your options, in full →A replacement that does not use Exchange Web Services.
- Connects Dynamics 365 on-premise to Exchange Online through the Microsoft Graph API.
- Nothing changes inside Dynamics. No schema changes and no customisations.
- Your Dynamics App for Outlook deployment carries on working.
- No third party touches your mailboxes or your CRM data.
What Prism Email Router does.
Built on the supported API
It reaches Exchange Online the modern, supported way, with no dependency on Exchange Web Services.
Your environment stays as it is
It works with your existing Dynamics 365 on-premise configuration. Configure the router and go.
Installed on your own server
We do not host or access your data. Everything stays inside your infrastructure, under your control.
Every kind of mailbox
Both user mailboxes and queue mailboxes are synchronised with Dynamics 365 on-premise.
Two things to set up
An Entra app registration for access to Exchange, and an Active Directory user account for access to Dynamics. The setup guides take you through both.
Keep using the Outlook app
The Dynamics App for Outlook goes on working, and we provide a guide to deploying and managing it.
Six Dynamics activities, kept in step with Outlook.
It is not only email. Emails, appointments, recurring appointments and tasks synchronise both ways. Service appointments and phone calls are pushed from Dynamics into Outlook.
Watch it working in the demo ↗- Emails · Outlook mailbox, both ways
- Appointments · Outlook calendar, both ways
- Recurring appointments · Outlook calendar, both ways
- Tasks · Outlook Tasks, both ways
- Service appointments · Outlook calendar, from Dynamics to Outlook
- Phone calls · Outlook Tasks, from Dynamics to Outlook
Dynamics 365 on-premise, and Dynamics CRM before it.
Prism Email Router supports every on-premise version that used Exchange Web Services for server-side sync.
Ready to move to Dynamics 365 Online instead?
Prism Email Router gives you time. It keeps an on-premise system working with Exchange Online until you are ready to move.
When you are, we can do that too. We have upgraded clients from Dynamics CRM 2011 and 2013 to Dynamics 365.
What we do on Dynamics 365 →