Microsoft Copilot and your on-premises Exchange Server - where things stand.
Microsoft 365 Copilot currently requires a mailbox in Exchange Online. For self-hosted Exchange Server, Microsoft has so far published an interest survey - no product. Postgate AI closes that gap today: set up once server-side, usable by all employees, each with their own Exchange permissions - in the familiar chat interface of Claude, ChatGPT, Perplexity or Mistral Vibe, on desktop and mobile. An add-in inside Outlook is available as an optional extra.
What Microsoft has announced for on-premises
A survey, not a product
In October 2025, the Microsoft Exchange team published an interest survey on "Copilot for Exchange Server (on-premises)" - no product, no roadmap, no confirmed architecture.
Timeline: years, if it happens at all
Experience shows that years typically pass between an interest survey and a shipped product - and whether Microsoft ships one at all remains open. If you want AI in your mailbox today, you need a solution that runs today.
Microsoft Copilot Studio and Postgate AI together
Microsoft Copilot Studio is the platform companies use to build their own AI agents and connect them to forms, knowledge bases, internal systems, and external tools. Since June 2026, Copilot Studio has supported MCP servers (Model Context Protocol) for this - the open standard through which AI assistants securely access external systems. Postgate AI is exactly such an MCP server and can be plugged into Copilot Studio as a tool: your Copilot agent gains access to on-premises mailboxes that it does not have natively. Postgate AI is not competing with Copilot here - it provides the connection to on-premises Exchange that Copilot itself does not offer today.
Frequently asked questions
Is Copilot coming to Exchange Server on-premises?
Unclear. Since October 2025 there has been an interest survey from Microsoft - no product, no roadmap. Experience shows that years typically pass between such a survey and an actual product, if one arrives at all.
Can I combine Postgate AI with Microsoft Copilot Studio?
Yes. Copilot Studio has supported MCP servers since June 2026, and Postgate AI can be plugged in as a tool there - via OAuth 2.0 with dynamic discovery, each user with their own Exchange permissions. Your Copilot agent gains the access to on-premises mailboxes that it does not have natively.
Do our emails leave the company?
Yes, for processing: requests and responses pass through our server in Germany - GDPR-compliant, with a DPA, like a transparent proxy without storage. Details on the security model page.
Which Microsoft Exchange versions are supported?
Microsoft Exchange Server Subscription Edition (SE), Exchange 2019 and Exchange 2016 via EWS - including versions whose Microsoft support ended in October 2025. Hybrid environments are supported as well.
AI in your on-premises mailbox - usable today
Try Postgate AI free for 7 days with your own Exchange - no credit card, ends automatically.