Microsoft Exchange Server 2019: Complete Buying Guide for Small Business

Microsoft Exchange Server is the backbone of business email for thousands of organizations worldwide. If you're setting up or upgrading your company's email infrastructure, understanding your licensing options can save you significant money.

This guide covers everything you need to know about buying Exchange Server 2019 — the latest on-premises version — including licensing, CALs, deployment options, and how it compares to Microsoft 365.

Quick Answer: Do You Need Exchange Server?

• Small business (1–25 users) wanting hosted email: Microsoft 365 is simpler — no server hardware needed
• Business needing on-premises email control: Exchange Server 2019 Standard — full control, compliance, data sovereignty
• Enterprise with 5,000+ mailboxes: Exchange Server 2019 Enterprise (up to 100 databases)

Exchange Server 2019: Standard vs Enterprise

Feature	Standard	Enterprise
Mailbox databases	5	100
Max server memory	128 GB	256 GB
High availability (DAG)	Yes	Yes
In-place archiving	No	Yes
DLP policies	No	Yes
Best for	SMBs (up to ~500 users)	Large enterprises

For most small and mid-sized businesses, Exchange Server 2019 Standard is the right choice. You get full email, calendar, and contacts functionality with high availability support.

Understanding Exchange CALs (Client Access Licenses)

Exchange Server requires a server license plus a CAL for each user or device that connects. This is a common licensing mistake — buying the server without CALs means your users can't legally connect.

Two types of CALs:

• User CAL: Covers one person across all their devices. Best when employees use multiple devices (laptop + phone + tablet).
• Device CAL: Covers one device for any user. Best for shared workstations or kiosks.

Rule of thumb: If your employees each have 2+ devices, User CALs are more cost-effective. If you have shared computers used by multiple people, Device CALs make more sense.

Exchange Server vs Microsoft 365: Which Is Right?

Factor	Exchange Server (On-Premises)	Microsoft 365 (Cloud)
Upfront cost	Server license + CALs	Monthly per-user fee
Ongoing cost	Hardware, IT maintenance	Subscription only
Data location	Your servers (full control)	Microsoft data centers
Compliance	Full control over data	Microsoft manages
IT expertise needed	Yes — server admin required	Minimal
Best for	Regulated industries, data sovereignty	Most small businesses

Choose on-premises Exchange if you need:

• Full control over your email data (legal, healthcare, government)
• Compliance with data residency requirements
• Custom mail flow rules and policies
• No recurring subscription costs after initial purchase

System Requirements for Exchange Server 2019

• OS: Windows Server 2019 Standard or later
• RAM: Minimum 128 GB recommended for Standard edition
• Storage: 30 GB minimum for Exchange install + mailbox storage
• Active Directory: Windows Server 2012 R2 forest functional level or later
• .NET Framework: 4.8 or later

Already running Windows Server 2022 or Windows Server 2025? Exchange 2019 is compatible with both.

How to Deploy Exchange Server 2019

1. Prepare Active Directory: Extend the schema and prepare your domain
2. Install prerequisites: .NET Framework 4.8, Visual C++ packages, UCMA 4.0
3. Run Exchange Setup: Use the GUI installer or command-line for unattended install
4. Configure mail flow: Set up send/receive connectors, DNS (MX, SPF, DKIM)
5. Apply your license key: Enter your product key in Exchange Admin Center
6. Add CALs: Assign CALs to users or devices through Volume Licensing

Need the server OS too? Check our Windows Server buying guide to pick the right version.

Common Mistakes When Buying Exchange Server

1. Forgetting CALs. The server license alone doesn't cover user access. Budget for User or Device CALs for every person/device connecting.
2. Buying Enterprise when Standard is enough. Unless you need 100+ mailbox databases or in-place archiving, Standard handles most SMB scenarios.
3. Not planning for Windows Server. Exchange 2019 runs on Windows Server — you need that license too. See our Windows Server collection.
4. Ignoring hybrid options. You can run Exchange on-premises alongside Microsoft 365 for a phased migration.

Why Buy from OfficeAndWin?

• Genuine Microsoft licenses — we're a Microsoft Partner
• Instant digital delivery — get your product key in minutes
• 21,000+ verified reviews — rated 4.71/5 on Judge.me
• Free activation support — we help with setup

Related Products

• Exchange Server 2019 Standard
• Windows Server 2019 Standard
• Windows Server 2022 Standard
• Windows Server 2025 Standard
• RDS CALs (Remote Desktop)

Frequently Asked Questions

How many CALs do I need for Exchange Server?

One CAL per user (User CAL) or per device (Device CAL) that connects to Exchange. If you have 20 employees, you need 20 User CALs or enough Device CALs to cover all connection points.

Can I upgrade from Exchange 2016 to 2019?

Yes. Exchange 2019 supports coexistence with Exchange 2016, allowing a phased migration. You'll need to update your Active Directory schema first.

Is Exchange Server 2019 still supported?

Yes. Microsoft extended support for Exchange Server 2019 runs until October 2025, with extended security updates available beyond that. It remains the current on-premises Exchange version.

Do I need Office licenses separately?

Yes. Exchange provides the email server; you still need Office licenses (like Outlook) for desktop email access. See our Office for small business guide.