What Is Microsoft Exchange Server?
Microsoft Exchange Server is the mail and calendar server behind corporate Outlook: it stores mailboxes, shares calendars and syncs mail to desktops and phones. Exchange 2016 and 2019 lost support on 14 October 2025. Organisations now choose Exchange Server SE on their own servers or Exchange Online inside Microsoft 365.
For IT managers and business owners running an old Exchange server, or deciding between Exchange Online and simpler business email.
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- Read time
- 4 min
- Sections
- 5
- Updated
- 14 Nov 2026
- Written by
- WebJi® team
Last editorial update: 14 November 2026. Prices follow the dated sources on this page; checkout confirms current charges.
What does Microsoft Exchange Server do?
Microsoft Exchange Server stores an organisation's mailboxes, calendars and contacts on its own servers, delivers mail for the company domain, and syncs everything to Outlook, Outlook on the web and phones. It is the engine behind the shared calendars, meeting rooms and delegated mailboxes that Outlook-based offices depend on.
- Mailboxes on your domain: you@company.in, with central quotas, retention policies and archiving.
- Calendaring and delegation: free/busy lookups, room booking, and assistants managing a manager's calendar.
- Exchange ActiveSync: push sync of mail, contacts and calendar to iOS and Android devices.
- Autodiscover: Outlook finds the server settings from the email address alone, so setup is mostly automatic.
- Directory integration: users and groups come from Active Directory, so one login covers Windows and mail.
Which Exchange Server versions are still supported?
Exchange Server 2016 and Exchange Server 2019 reached end of support on 14 October 2025; the supported on-premises version is now Exchange Server Subscription Edition (SE), and the cloud option is Exchange Online. Unsupported servers keep running but no longer receive security fixes, bug fixes or time-zone updates.
| Version | Status | Upgrade path |
|---|---|---|
| Exchange 2013 and earlier | Unsupported | Must be removed before installing 2019 CU15 or SE |
| Exchange 2016 | Support ended 14 October 2025 | Side-by-side move to a newer version; no in-place upgrade to SE |
| Exchange 2019 | Support ended 14 October 2025 | In-place upgrade to SE from Cumulative Update 15 |
| Exchange Server SE | Current on-premises release (from July 2025) | Subscription licensing |
| Exchange Online | Microsoft-run cloud service | Part of Microsoft 365 plans |
Microsoft's own recommendation in its end-of-support notice is to move to Exchange Online, or to upgrade to Exchange SE if mail must stay on-premises.
Exchange Server vs Exchange Online
Exchange Server is software you install and run on your own Windows Server machines; Exchange Online is the same mail platform run by Microsoft inside Microsoft 365 and billed per user. The difference is who owns the hardware, the patching and the risk.
| Exchange Server (on-premises) | Exchange Online | Hybrid | |
|---|---|---|---|
| Who runs servers | You | Microsoft | Both |
| Licensing | Server licences plus user CALs (subscription for SE) | Per user per month or year | Both |
| Patching and security | Your team, on every update | Microsoft | Your servers are still yours |
| Where mail is stored | Your data centre | Microsoft's cloud | Split by mailbox |
| Typical use | Strict data-residency or legacy integration needs | Most small and mid-size businesses | A staged migration |
Should you run Exchange Server yourself on a VPS?
Rarely: self-hosted Exchange needs Windows Server and Exchange licences, user CALs, Active Directory, Exchange-aware backups and prompt patching, and it is one of the most attacked mail platforms on the internet. The ProxyLogon vulnerabilities of 2021 showed how fast unpatched Exchange servers are compromised.
It makes sense mainly for larger organisations that already run Windows infrastructure, have an administrator on staff, and must keep mail on their own hardware. A single VPS also gives no redundancy: if it fails, mail stops. If you need control over mail data without the licensing, a standard mail stack on a Windows or Linux VPS costs far less; if you want the Outlook experience, Exchange Online is cheaper once all licences are counted.
Exchange Online, Google Workspace or plain business email?
Choose Exchange Online through Microsoft 365 if your team lives in Outlook and Teams, Google Workspace if it works in Gmail and Docs, and plain business email hosting if you only need reliable mailboxes on your domain.
| Option | Entry price | Includes |
|---|---|---|
| Microsoft 365 Business Basic | ₹170 per user per month, annual commitment (list price recorded 29 October 2026) | Exchange Online mailbox, web and mobile Office, Teams, 1 TB OneDrive |
| Google Workspace Business Starter | ₹3,240 per user per year | Gmail on your domain, Drive, Docs, Meet |
| WebJi® business email | ₹2,520 a year for five 5 GB mailboxes | Mailboxes, webmail, IMAP/SMTP |
Checkout confirms current prices. The two suites are compared in Google Workspace vs Microsoft 365, and what makes any domain mailbox a business address is explained in what a business email address is.
How to migrate off an old Exchange Server
Every Exchange migration follows the same order: inventory, create the destination accounts, copy mail while both systems receive it, then switch MX and confirm delivery before switching the old server off.
- List every mailbox, shared mailbox, distribution group, room and public folder on the old server.
- Create the destination users: a Microsoft 365 tenant for Exchange Online, Google Workspace users, or mailboxes on a business email plan.
- Copy the mail. Exchange Online has native migration from on-premises Exchange; Google Workspace has its own data migration service; other hosts use IMAP sync.
- Keep the old server receiving mail while the copy finishes, then run a final sync.
- Change the MX record and Autodiscover DNS to the new provider, and set up Outlook profiles again where needed.
- Confirm mail flows in both directions for a few days before decommissioning the old server.
MX changes are explained in what an MX record is; mailbox copying in how to migrate email accounts; and reconnecting Outlook in setting up business email in Outlook.
Frequently asked questions
Is Outlook the same as Exchange?
No. Outlook is the email app on your computer, phone or browser; Exchange is the server that stores the mailbox. Outlook can also connect to Gmail or any IMAP mailbox, and an Exchange mailbox can be opened in other apps through ActiveSync.
What happens if we keep running Exchange 2016 or 2019?
The servers keep working, but since 14 October 2025 Microsoft no longer issues security fixes, bug fixes or time-zone updates for them. Any newly discovered vulnerability stays open, which matters for a server that must face the internet to receive mail.
What is Autodiscover in Exchange?
Autodiscover is the service that gives Outlook and phones the server settings from just an email address and password. It relies on a DNS record for the domain, so after a migration that record must point to the new provider or Outlook keeps looking for the old server.
Can I use Exchange features without Microsoft 365?
Only by running Exchange Server SE yourself or buying Exchange Online as a standalone service. Plain IMAP mailboxes handle mail well but offer only basic calendar sharing, so teams that rely on room booking and delegation usually stay on Exchange in some form.
Version and support dates checked against Microsoft's Exchange Team announcements on 14 November 2026 · Reviewed by the WebJi® team, Jaipur.
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