The Dangerous Gamble: Why Running Exchange Server After EOL Is a Business Risk You Can’t Afford

July 1, 2025

Whether you're a small business, a municipality, or a large enterprise, if you're still running Microsoft Exchange Server 2016 or 2019, there's a major deadline looming:


October 14, 2025 - End of Life.


After this date, Exchange 2016 and 2019 will no longer receive security updates, patches, or support from Microsoft. And if you're on something older? You're already living dangerously.


Let’s break down why continuing to use Exchange after EOL (end of life) is one of the riskiest moves ANY business can make.


🚨 1. No Security Patches = You’re a Sitting Duck

Once Microsoft ends support, any new vulnerabilities in Exchange will go unpatched, FOREVER.

That means:

  • Hackers can exploit known and unknown bugs without resistance.
  • Your business email becomes an easy target for ransomware, phishing, and data theft.
  • Past Exchange vulnerabilities like ProxyLogon and ProxyShell were exploited within hours, and these were while still under support.


Imagine what happens when nobody’s watching your back.


📉 2. You’re Likely Violating Compliance, Even If You Don’t Know It

Running outdated, unsupported software often puts you out of compliance with:

  • Cyber liability insurance policies
  • Industry standards (like HIPAA, CJIS, PCI-DSS, FTC Safeguards, etc.)
  • State and federal cybersecurity laws


Most businesses don't realize that insurance claims can and WILL be denied if you're running unsupported systems. One missed update could be the difference between protection and a six to seven figure recovery bill.


🎯 3. You’re a Target, Even If You’re Small

There’s a dangerous myth that only big companies get hacked. This is simply NOT true.

Hackers don’t discriminate; they automate. They scan the internet looking for:

  • Open ports
  • Known vulnerabilities
  • Outdated systems (like unsupported Exchange servers)


And when they find one? They don’t knock, they walk right in.


In fact, 60% of small businesses go out of business within six months of a major cyberattack. Don’t assume you’re too small to be on someone’s radar.


🔄 4. No Microsoft Support = You're On Your Own

After EOL (end of life):

  • Microsoft won't help you, even if your mail server crashes.
  • Third-party tools (antivirus, backup, monitoring) may stop supporting your version.
  • If something breaks, there’s no one to call.


Your email is too mission-critical to rely on hope.


✅ What Should You Do?

You have two responsible paths forward:

🔹 Migrate to Exchange Online (Microsoft 365)

  • Cloud-hosted, secure, and always updated
  • Reduces your maintenance and infrastructure costs
  • Adds built-in resilience


🔹 Upgrade to Exchange Server Subscription Edition (SE)

  • Released in July 2025
  • Subscription-based model (no more perpetual licenses)
  • In-place upgrade possible from Exchange 2019 CU15
  • Keeps email on-prem for businesses with strict compliance needs


⚠️ If You Must Delay, Do This Immediately

If you're not ready to migrate or upgrade yet:

  • Remove internet access to your Exchange server
  • Implement advanced threat protection and endpoint detection (EDR)
  • Enforce multi-factor authentication
  • Test your backups and disaster recovery plans
  • Schedule a penetration test to find your weak spots


But be clear: these are short-term bandaids, not solutions.


🧠 Final Thoughts

Email is the gateway to your business. It's where invoices go out, credentials are stored, contracts are sent, and operations are coordinated. Leaving it running on unsupported software is a disaster waiting to happen.


Are you getting the gist? Every business needs to take cybersecurity seriously—now.


Whether you're a
city government, school district, hospital, insurance firm, manufacturing plant, CPA firm, law office, healthcare provider, construction company, retail chain, nonprofit, financial institution, and the list goes on, the need for cybersecurity applies to you.


If your organization uses email, stores sensitive data, or simply wants to stay in business, cybersecurity isn't optional.


The clock is ticking.


The longer you wait, the higher the risk, and the fewer options you’ll have when something goes wrong.


Don't be the next breach headline. Be the one who acted early.


If you're not sure where to begin, we can help you evaluate your options and move toward a secure, supported future, whether that’s cloud or on-prem.


Reach out today. Before a hacker does.