Navigating the End of Support for Microsoft Exchange 2019: Your Options and Best Practices

OVERVIEW 

Microsoft will end support for Exchange Server 2016 and 2019 on October 14, 2025, leaving users without security updates or technical support, which increases vulnerability to cyber threats. Organizations should consider either upgrading to Exchange Server Subscription Edition for on-premises control or migrating to Exchange Online for a fully managed cloud solution, while planning early and assessing their unique needs.

INDEPTH

On October 14, 2025, Microsoft will officially end support for Exchange Server 2016 and 2019, marking a significant milestone for organizations that rely on these platforms for email and collaboration. After this date, Microsoft will cease providing security updates, bug fixes, and technical support, leaving systems vulnerable to cyber threats and operational challenges. For businesses using Exchange 2019, now is the time to evaluate your options: upgrading to Microsoft Exchange Server Subscription Edition (SE) or migrating to Exchange Online. 

This article provides a comprehensive guide to both paths, detailing their pros and cons, pricing, migration strategies, and best practices to allow for a seamless transition. By understanding these options, you can make an informed decision that aligns with your organization’s needs and goals.

Understanding the End of Support

The end of support for Exchange Server 2019, scheduled for October 14, 2025, means that Microsoft will no longer release security patches, bug fixes, or offer technical assistance for this version. Continuing to use an unsupported server increases the risk of data breaches, ransomware, and operational disruptions due to unpatched vulnerabilities. This deadline, confirmed by Microsoft’s Fixed Lifecycle Policy, applies to both Enterprise and Standard editions of Exchange 2019. To maintain a secure and reliable email environment, organizations must act proactively to either upgrade their on-premises infrastructure or transition to a cloud-based solution.

Option 1: Upgrading to Exchange Server Subscription Edition (SE)

What is Exchange SE?

Microsoft Exchange Server Subscription Edition (SE), released on July 1, 2025, is the successor to Exchange 2019, designed for organizations that require on-premises email solutions due to compliance, data residency, or operational preferences. Built on the same code as Exchange 2019 Cumulative Update 15 (CU15), Exchange SE introduces a subscription-based licensing model and follows Microsoft’s Modern Lifecycle Policy. This policy allows ongoing updates without a fixed end date, provided configurations remain current. Exchange SE supports hybrid deployments, allowing coexistence with Exchange Online for organizations transitioning gradually.

Pros of Exchange SE

• On-Premises Control: Retains complete control over data and infrastructure, critical for industries with strict compliance or data sovereignty requirements.
• Familiar Interface: Leverages the same management tools as Exchange 2019, minimizing the learning curve for IT teams.
• Cost Efficiency for Existing Infrastructure: Organizations with robust on-premises setups may find it cost-effective to continue using existing hardware.
• Hybrid Compatibility: Supports hybrid environments, enabling a phased migration to the cloud if desired.

Cons of Exchange SE

• Ongoing Maintenance: IT teams must manage server updates, security, and maintenance, increasing operational overhead.
• Licensing Costs: Requires active Software Assurance (SA) or cloud subscription licenses, potentially raising expenses.
• Limited Innovation: Lacks access to cloud-exclusive features like Microsoft 365 CoPilot CoPilot is a collaborative AI-powered tool or assistant designed to enhance productivity and decision-making. CoPilot helps users by providing suggestions, automating tasks, and offering insights, acting as a supportive partner to streamline workflows and improve efficiency across various applications. , limiting exposure to cutting-edge advancements.

Pricing for Exchange SE

Pricing for Exchange SE reflects a 10% increase in standalone on-premises server licenses, effective July 2025. Additionally, organizations must maintain active Software Assurance or cloud subscription licenses (e.g., Microsoft 365 E3 or E5) for all users and devices accessing the server. Client Access License (CAL) suites have also seen price increases: the Core CAL Suite by 15% and the Enterprise CAL Suite by 20%. Exact costs vary based on the number of users and existing licensing agreements; therefore, consulting a Microsoft representative is recommended for obtaining precise quotes.

Migration to Exchange SE

Upgrading to Exchange SE is straightforward for organizations on Exchange Server 2019 Cumulative Update 15, as it supports an in-place upgrade. Key steps include:

• Verify that your server is running Exchange 2019 Cumulative Update 15.
• Make sure all prerequisites, such as compatible Windows Server versions (2019, 2022, or 2025), are met.
• Confirm active Software Assurance or cloud subscription licenses.
• Test the upgrade in a non-production environment to identify potential issues.

Option 2: Migrating to Exchange Online

What is Exchange Online?

Exchange Online is Microsoft’s cloud-based email and collaboration platform, integrated into Microsoft 365. It offers a fully managed service, eliminating the need for on-premises hardware and providing automatic updates, scalability, and access to advanced features, such as Microsoft 365 CoPilot CoPilot is a collaborative AI-powered tool or assistant designed to enhance productivity and decision-making. CoPilot helps users by providing suggestions, automating tasks, and offering insights, acting as a supportive partner to streamline workflows and improve efficiency across various applications. . Exchange Online integrates seamlessly with other Microsoft 365 services, including SharePoint, Teams, and OneDrive, to create a comprehensive productivity suite.

Pros of Exchange Online

• Fully Managed Service: Microsoft handles maintenance, updates, and security, reducing IT workload.
• Advanced Features: Includes AI Artificial Intelligence (AI) refers to the simulation of human intelligence processes by machines, particularly computer systems. In the IT and digital marketing industry, AI is transforming the way businesses operate by enabling machines to analyze data, learn patterns, and make decisions with minimal human intervention. AI is widely used in chatbots, personalized marketing campaigns, predictive analytics, and customer behavior analysis. It helps optimize ad performance, improve user experiences, and target the right audience with precise data-driven insights. From automating repetitive tasks to delivering actionable marketing strategies, AI has become a critical tool for innovation and efficiency in the digital landscape. -driven tools like Microsoft 365 CoPilot CoPilot is a collaborative AI-powered tool or assistant designed to enhance productivity and decision-making. CoPilot helps users by providing suggestions, automating tasks, and offering insights, acting as a supportive partner to streamline workflows and improve efficiency across various applications. and integrates with other Microsoft 365 applications.
• Scalability and Flexibility: Easily scales to accommodate growing organizations without hardware upgrades.
• Enhanced Security: Benefits from Microsoft’s robust cloud security infrastructure, including regular updates and threat protection.

Cons of Exchange Online

• Internet Dependency: Requires a stable internet connection, which may be a challenge in areas with unreliable connectivity.
• Data Sovereignty Concerns: Cloud storage may raise compliance issues for organizations in regulated industries.
• Potential Cost Increases: Subscription-based pricing can be higher for large organizations compared to on-premises setups.

Pricing for Exchange Online

Exchange Online is typically bundled within Microsoft 365 plans, with pricing as follows (as of July 2025):

• Microsoft 365 Exchange Online: $4/user/month, includes ONLY the Exchange Online license.
• Microsoft 365 Business Basic: $6/user/month, includes Exchange Online and basic Microsoft 365 apps.
• Microsoft 365 Business Standard: $12.50/user/month, adds desktop apps and enhanced features.
• Microsoft 365 Business Premium/Enterprise: $23-$57/user/month, offering advanced security and compliance features. Specifics of the plan are available, and pricing may vary depending on organizational needs. Check Microsoft’s official pricing page for the latest details: Microsoft 365 Plans.

Migration to Exchange Online

Migrating to Exchange Online involves several methods, depending on your organization’s size and complexity:

• Cutover Migration: Ideal for small organizations with fewer than 2,000 mailboxes, this method moves all mailboxes simultaneously.
• Staged Migration: Suitable for larger organizations, allowing gradual migration over time.
• Hybrid Migration: Enables coexistence with on-premises Active Directory, making it ideal for organizations that need a phased transition. Each method requires careful planning, including assessing mailbox sizes, network bandwidth, and the potential impact on users.

Comparison Table

Best Practices for Migration

To allow for a smooth transition to either Exchange SE or Exchange Online, follow these best practices:

1. Plan Early: Begin planning at least six months before the October 2025 deadline to avoid disruptions.
2. Assess Needs: Evaluate whether on-premises or cloud solutions align with your compliance, budget, and operational goals.
3. Backup Data: Perform full backups of all mailboxes and configurations before starting the migration.
4. Test Thoroughly: Use a non-production environment to test the migration process and identify potential issues.
5. Communicate with Users: Inform users about the migration timeline, potential downtime, and training needs.
6. Monitor Post-Migration: After migration, monitor system performance and user feedback to optimize the setup.

How Can Intrada Help?

The end of support for Microsoft Exchange Server 2019 on October 14, 2025, is a pivotal moment for organizations to reassess their email and collaboration strategies. Upgrading to Exchange Server Subscription Edition offers continuity for on-premises environments, while migrating to Exchange Online provides scalability and modern features. By considering the advantages, disadvantages, costs, and migration needs, along with following best practices, businesses can achieve a secure and efficient transition. For customized guidance, contact Intrada Technologies to explore how we can support your migration journey.