Microsoft Exchange Server Support Services
Database won't mount at 3 AM? Mail flow dead? DAG split-brain? 8-minute average phone response. 1,247 Exchange incidents resolved. MCSA-certified engineers on every ticket. Exchange 2010/2013/2016/2019/SE all supported — including EOL versions.
Your mail is down. Your MSP is asleep.
Database won't mount and 180 users are locked out. Our admin answered in 11 minutes and had Exchange back up by 5:10 AM.
Commodity MSP response time while mail flow is dead. Ours is under 15 min — routed to MCSA-certified engineers, not Tier 1.
Average cost of one hour of Exchange outage for a 200-mailbox org. Our proactive plan prevents it before users notice.
Recovery rate on crashed Exchange databases. Average fix time 2.3 hours. We support 2010/2013 that other MSPs refuse.
Every Exchange subsystem, covered.
CU/SU Failed Install Recovery
When a Cumulative Update or Security Update breaks Exchange — services won't start, OWA returns 503, app pools stopped — we recover. Most common after Patch Tuesday: post-CU service-startup ordering, IIS app-pool identity issues, missing prerequisites.
Database Won't Mount / Dirty Shutdown
Eseutil /mh state confirmation, soft recovery from log files, hard repair only when log gap forces it. Most database mount failures are recoverable without data loss when caught within hours.
DAG Repair & Split-Brain
Database Availability Group copy failures, FailedAndSuspended status, divergence repair, re-seed vs resume decision based on log gap size, content-index rebuilds, failover validation.
Mail Flow & Queue Backlogs
Transport service stuck, queue over 10,000 messages, NDR storms, connector misconfig, Safety Net replay, edge transport rules, DKIM/DMARC, third-party gateway integration.
Certificate Renewal & OWA Recovery
Expired SSL/TLS breaking OWA, ActiveSync, Autodiscover. Fast cert reissue, Enable-ExchangeCertificate binding, IIS rebind, force service restart. Same-business-day resolution typical.
Hybrid Coexistence & M365 Integration
Hybrid Configuration Wizard, free/busy federation, cross-premises mail flow, Azure AD Connect sync, OAuth trust setup, hybrid mailbox moves, post-M365-change drift repair.
Migrations: 2016/2019 → SE or M365
Exchange Server SE in-place upgrade from 2019 CU15. Cutover, staged, and hybrid migrations to Microsoft 365. ESU enrollment guidance for orgs that need 2016/2019 to keep running through Oct 2026.
What you should be running.
Reference table updated monthly. If you're below the latest SU, you have unpatched vulnerabilities. Last updated: 2026-04-25
Exchange Server SE (Subscription Edition)
CurrentSupported through at least December 31, 2035
| Release | Build | Date | KB |
|---|---|---|---|
| SE RTM + Feb 2026 SULatest | 15.02.2562.37 | Feb 10, 2026 | KB5074992 |
| SE RTM + Dec 2025 SU | 15.02.2562.35 | Dec 9, 2025 | KB5071876 |
| SE RTM + Oct 2025 SU | 15.02.2562.29 | Oct 14, 2025 | KB5066366 |
| SE RTM (initial) | 15.02.2562.17 | Jul 1, 2025 | — |
Exchange Server 2019
EOL · ESU availableMainstream support ended Oct 14, 2025. ESU coverage extended through Oct 2026.
| Release | Build | Date | KB |
|---|---|---|---|
| CU15 + Feb 2026 SULatest | 15.02.1748.43 | Feb 10, 2026 | KB5074993 |
| CU15 + Dec 2025 SU | 15.02.1748.42 | Dec 9, 2025 | KB5071875 |
| CU15 + Oct 2025 SU | 15.02.1748.39 | Oct 14, 2025 | KB5066367 |
| CU15 (base) | 15.02.1748.10 | Feb 10, 2025 | — |
| CU14 + Feb 2026 SU | 15.02.1544.39 | Feb 10, 2026 | KB5074994 |
Exchange Server 2016
EOL · ESU availableMainstream support ended Oct 14, 2025. ESU coverage extended through Oct 2026 for enrolled customers.
Exchange Server 2013
End of LifeEnd of life April 11, 2023. No further updates. Migrate to Exchange SE or Microsoft 365.
Find your build: Open Exchange Management Shell and run Get-Command Exsetup.exe | ForEach-Object {$_.FileVersionInfo} — compare ProductVersion against the table above. If you're below the latest SU, we patch in your maintenance window (typical 90 min/server with full validation). Schedule a CU/SU patch →
Source of truth: Microsoft Learn — Exchange Server build numbers and release dates
Fixed pricing. No surprises.
Enterprise plans with dedicated engineers are custom-quoted for 20+ servers. All plans include MCSA-certified administrators, ISO 27001 security, EOL Exchange support (2010/2013), no setup fees, and cancel-anytime flexibility. Example: 3 servers = $897/month (or $765/month annual).
The engineers on call.
No tier-1 helpdesk. No outsourced ticket triage. When you call, one of these three picks up.
Sreenivasa Reddy
Founder & Principal Exchange Engineer
MCSE Messaging · 25 yrs on Exchange (5.5 → SE)
Operates the on-call rotation. Has personally recovered hundreds of dismounted databases, debugged DAG split-brain across multi-site deployments, and led 500+ Exchange-to-M365 migrations. Direct line for P1 incidents.
Roshan Pujari
Senior Exchange Engineer
Microsoft Certified · Exchange + M365
CU/SU patching specialist. Owns the staging-validate-rollback workflow we use before any production patch. Leads hybrid coexistence and OAuth trust setups.
Bhargav
Senior Exchange Engineer
Microsoft Certified · Exchange Messaging
Mail flow and transport-layer lead. Specializes in queue diagnosis, anti-spam tuning (Safety Net, edge rules), DKIM/DMARC enforcement, and third-party gateway integrations.
How we actually work.
Two recent engagements, anonymized. Symptoms → diagnosis → fix → outcome. The same structure shows up in every P1 we run.
Logistics / Fleet Operations · Calgary, Canada · April 2025
Post-CU install: Outlook + OWA + ActiveSync all down
Symptoms
Customer installed the latest Exchange CU plus OS updates over the weekend. Monday morning: Outlook desktop wouldn't connect, OWA returned HTTP 503 after credentials, ActiveSync dead. Last successful mail delivery was Saturday evening. Backup power supply had failed — suspected unclean shutdown during the patch window.
Diagnosis
Confirmed Exchange services in mixed state — MSExchangeServiceHost running, MSExchangeIS stopped. IIS app pools (MSExchangeOWAAppPool, MSExchangeECPAppPool, MSExchangeAutodiscoverAppPool) were stopped. Setup log showed CU install had completed but post-install service ordering failed during the unclean reboot.
Fix
Started the stopped services in the correct order (IS first, then dependent app pools), recycled IIS, verified Test-ServiceHealth returned all green. Mailbox database mounted clean — no eseutil /r needed because the unclean shutdown predated the CU completion. Mail flow restored within 90 minutes of engagement.
Outcome
OWA, ActiveSync, and Outlook desktop all functional. No mailbox data loss. Customer email queue caught up within 2 hours.
Public Sector Manufacturing · New Delhi, India · April 2025
Annual AMC renewal — Exchange Server 2019, multi-site
Symptoms
Government-sector customer's comprehensive AMC for Exchange Server 2019 was approaching renewal. Required GST-compliant invoicing, defined SLA tiers (P1 / P2 / P3 response targets), and quarterly health reports. Existing on-prem Exchange 2019 deployment with multi-site DAG.
Diagnosis
Reviewed prior year's incident log: average 4 P1s per quarter (mostly mail flow + cert renewal), 11 P2s, no P3 escalations. Confirmed customer's deployment was on Exchange 2019 CU15 — eligible for ESU enrollment through Oct 2026 to keep receiving Security Updates.
Fix
Renewed comprehensive AMC for 12 months with structured scope: 24/7 P1 response (≤15 min), monthly proactive patching window, quarterly DAG failover validation, GST-compliant monthly invoices, dedicated engineer assignment. Included ESU enrollment paperwork as part of the renewal.
Outcome
AMC renewed on time, ESU enrolled, deployment continues to receive monthly Security Updates from Microsoft. Customer's preferred path: ride out 2019 with ESU through Oct 2026, then evaluate Exchange SE vs M365 migration.
Frequently Asked Questions
Exchange Server 2016 and 2019 hit end of life in October 2025 — should we still run them?+
What is Exchange Server Subscription Edition (SE) and should we migrate to it?+
What's your response time when Exchange is down right now?+
What's the latest Exchange Server build we should be on?+
A CU or SU install just broke our Exchange — can you recover it?+
Our database won't mount — is the data lost?+
Do you support Exchange in India and handle GST-compliant invoicing?+
How do you secure remote access to our Exchange servers?+
What's the difference between Reactive and Proactive support plans?+
Can you migrate us off Exchange entirely — to Microsoft 365?+
Mail down? Call us now.
8-min avg phone answer. 1,247 incidents resolved. MCSA-certified engineers. From $299/server/month.
Server Administration & Troubleshooting Articles
Exchange Server 2016 & 2019 End of Life — What Are Your Options? (2026)
Microsoft ended support for Exchange Server 2016 and 2019 on October 14, 2025. If you are still running either, here is what happens next and your three realistic options.
Exchange Server to Microsoft 365 Migration 2026: Complete Guide for Exchange 2013, 2016, and 2019
Exchange Server 2016 and 2019 reached end of support in October 2025. This complete migration guide covers hybrid, cutover, and staged migration paths to Exchange Online with step-by-step instructions, tool comparisons, and timeline estimates.
Exchange Server to Microsoft 365 Migration — Complete Guide (2026)
Battle-tested migration playbook from 500+ enterprise Exchange-to-Microsoft-365 migrations. Covers hybrid, cutover, staged, and IMAP methods with step-by-step walkthroughs, real-world gotchas, timeline sizing, and post-migration checklists.
Exchange Server Supportability Matrix
Managing Microsoft Exchange Server environments can be complex — especially when trying to stay compliant with supported versions, OS builds, Active Directory, and client compatibility. That’s why this Exchange Server Supportability Matrix is your go-to guide. Whether you’re upgrading to Exchange Server 2019 CU15, planning a migration to Exchange Server SE, or ensuring browser and […]