Exchange Consulting & Emergency Support
Migration services, hybrid deployments, and 24/7 emergency response for enterprise email infrastructure.
Last updated by Errin O'Connor, Founder & Chief AI Architect, EPC Group
EPC Group provides Microsoft Exchange Server consulting, migration to Exchange Online (Microsoft 365), and 24/7 emergency support. Exchange Server 2019 reached end-of-life in October 2025. If you are still on-premises, now is the time to migrate. EPC Group has migrated 3.7 million+ mailboxes with a 5-day average cutover.
Key Facts
- Exchange Server 2019 end-of-life: October 2025. No new security patches after that date.
- 3.7 million+ mailboxes migrated to Microsoft 365 by EPC Group.
- Migration types: cutover (under 150 mailboxes), staged (150–2,000), hybrid (2,000+).
- Microsoft Solutions Partner — core designations including Modern Work.
- Exchange Since 1997 and Microsoft 365 consulting. Founded 1997.
Microsoft Exchange Experts Since 1997
With the end-of-life for Exchange Server coming in October 2025, planning your migration strategy is essential. The move to subscription-based licensing is altering the cost structure of on-premises deployments.
EPC Group has successfully completed over 6,500 Exchange migrations for various enterprises, including:
- Organizations with 50 users
- Fortune 500 companies with over 100,000 mailboxes
Exchange Migration Services
Whether you're moving from on-premises Exchange to the cloud, consolidating tenants, or implementing a hybrid deployment, our certified engineers ensure a seamless transition.
On-Premises to Exchange Online
Complete migration from Exchange Server 2013/2016/2019 to Exchange Online with documented data-fidelity checklists, pre-cutover reconciliation, and minimal downtime.
- Hybrid deployment configuration
- Cutover and staged migrations
- PST import and archive migration
- Public folder migration
Hybrid Exchange Deployments
Maintain both on-premises and cloud mailboxes with seamless integration, shared calendars, and unified address book.
- Hybrid Configuration Wizard setup
- OAuth authentication
- Free/busy sharing
- Cross-premises mail flow
Exchange Server Upgrades
Upgrade legacy Exchange environments to supported versions before migrating to the cloud.
- Exchange 2010/2013 to 2019 upgrades
- Database availability groups (DAG)
- SSL certificate management
- Cumulative update deployment
Tenant-to-Tenant Migration
Migrate mailboxes between Microsoft 365 tenants during M&A, divestitures, or organizational restructuring.
- Cross-tenant mailbox migration
- Calendar and contact preservation
- Distribution list migration
- Shared mailbox handling
Exchange Server Down? We're On It.
When Exchange fails, your business stops. Our US-based Microsoft Certified Engineers are available around the clock to diagnose and resolve critical Exchange issues—remotely or on-site.
Failed Cumulative Updates
15-minute responseExchange CU updates can fail catastrophically. Our engineers diagnose and resolve failed updates, corrupted installations, and rollback scenarios.
Email Flow Restoration
15-minute responseMail not flowing? We troubleshoot and restore mail flow issues including connector problems, DNS misconfigurations, and transport rule conflicts.
Database Recovery
30-minute responseRecover from database corruption, dismounted databases, and failed database availability groups. We restore service and recover lost data.
Security Incidents
Immediate responseRespond to Exchange security breaches, compromised accounts, and zero-day vulnerabilities like ProxyLogon and ProxyShell.
Disaster Recovery
30-minute responseComplete Exchange environment recovery from hardware failures, ransomware attacks, or catastrophic data loss scenarios.
Performance Issues
1-hour responseDiagnose and resolve slow performance, high CPU utilization, memory pressure, and storage bottlenecks affecting Exchange.
Microsoft Certified Engineers • 15-Minute Response • 100% US-Based
Exchange Versions We Support
From legacy Exchange 2010 to the latest Exchange Online, we've got you covered.
Exchange Server 2016/2019 End of Support: October 2025
Microsoft has announced that Exchange Server 2016 and 2019 will reach the end of extended support in October 2025. Organizations using on-premises Exchange need to take action.
- Migrate to Exchange Online.
- Upgrade to Exchange Server SE (Subscription Edition), which offers subscription-based licensing.
Note that the upgrade may involve cost increases of 10-20%.
Your Options:
- Migrate to Exchange Online – Move to Microsoft's cloud-hosted Exchange with predictable per-user pricing and no server maintenance.
- Hybrid Deployment – Keep some mailboxes on-premises while moving others to the cloud for a gradual transition.
- Upgrade to Exchange SE – Stay on-premises with the new subscription-based Exchange Server (requires Software Assurance).
Plan Your Exchange Migration Today
Don't wait until October 2025. Our Exchange migration assessments identify risks, estimate timelines, and create a roadmap for a successful transition to Exchange Online.
Frequently Asked Questions
What Microsoft 365 consulting services does EPC Group provide?
EPC Group provides M365 deployment, migration, governance, security configuration, Copilot readiness, compliance setup, and managed services. We specialize in enterprise M365 environments with 1,000+ users requiring HIPAA, SOC 2, or FedRAMP compliance.
How much does Microsoft 365 consulting cost?
M365 consulting is scoped to the engagement: a focused migration, an enterprise governance and security implementation, or full platform optimization with Copilot. EPC Group offers fixed-price engagements.
Can EPC Group help with Microsoft 365 compliance?
Yes. EPC Group configures Microsoft 365 compliance features including retention policies, DLP, sensitivity labels, eDiscovery, communication compliance, and information barriers. We map these controls to specific frameworks: HIPAA, SOC 2, FedRAMP, GDPR, and CCPA.
How does EPC Group handle M365 tenant-to-tenant migrations?
EPC Group manages complex tenant-to-tenant migrations for M&A scenarios including mailbox migration, SharePoint content, Teams channels, OneDrive data, security groups, and conditional access policies. We use BitTitan, ShareGate, and custom PowerShell for seamless coexistence during transition.
Why Organizations Choose EPC Group
EPC Group is a Microsoft consulting firm based in Houston. We have experience in enterprise implementation since 1997 and over 10,000 successful deployments. Our expertise includes:
- Power BI
- Microsoft Fabric
- SharePoint
- Azure
- Microsoft 365
- Copilot
We serve organizations in various sectors, including Fortune 500 companies, federal agencies, healthcare, financial services, government, manufacturing, energy, education, retail, technology, and global enterprises.
What sets EPC Group apart is our governance-first approach. Every engagement starts with a security and compliance assessment. Our senior architects have practical experience in:
- HIPAA
- SOC 2
- FedRAMP
- CMMC environments
We focus on delivering results, not just hours worked.
- Fixed-fee accelerators with predictable pricing and defined deliverables
- Senior architect engagement on every project, not rotating juniors
- Compliance-native delivery for regulated industries
- End-to-end coverage from strategy through 24/7 managed services
- 11,000+ enterprise engagements refined into repeatable, risk-controlled patterns
Call (888) 381-9725 or email contact@epcgroup.net for a free assessment.
Exchange Server Consulting & Migration to Exchange Online
EPC Group offers Microsoft Exchange Server consulting, migration to Exchange Online (Microsoft 365), and 24/7 emergency support.
Exchange Server 2019 will reach end-of-life in October 2025. If you are still using on-premises solutions, now is the time to migrate.
- EPC Group has successfully migrated over 3.7 million mailboxes.
- Every migration ships with documented data-fidelity checklists and pre-cutover reconciliation.
Exchange consulting services
EPC Group covers the full Exchange lifecycle — from on-premises administration through migration to Exchange Online and post-migration managed services.
- Exchange health assessment — audit of current on-premises Exchange environment, database health, transport rules, and hybrid readiness.
- Migration planning — approach selection, timeline planning, wave design, and cutover scheduling.
- Migration execution — phased or cutover migration with zero-downtime mail flow and data integrity validation.
- Hybrid Exchange setup — coexistence between on-premises Exchange and Exchange Online for gradual migration.
- Tenant-to-tenant migration — mailbox migration between Microsoft 365 tenants (M&A, divestiture, consolidation).
- Emergency support — 24/7 response for mail flow failures, database corruption, and security incidents.
Migration approach by organization size
The right migration approach depends on mailbox count and business requirements. EPC Group selects and configures the appropriate method for each engagement.
| Approach | Mailbox count | Description |
|---|---|---|
| Cutover migration | Under 150 | All mailboxes migrate at once. Fastest method. |
| Staged migration | 150–2,000 | Batches over weeks. On-premises Exchange remains active during migration. |
| Hybrid migration | 2,000+ | Coexistence. Mailboxes move in waves. Best for large enterprises. |
| Tenant-to-tenant | Any | Moves mailboxes between Microsoft 365 tenants. M&A and restructuring. |
| Google Workspace migration | Any | Microsoft's Google Workspace (Gmail) batch migration: mail, rules, calendars and contacts. Not available for GCC High / DoD. |
| IMAP migration | Any | For other non-Exchange sources. Mail only — calendars, contacts and rules do not migrate. |
Why migrate from Exchange Server now?
Exchange Server 2019 reached end-of-life in October 2025. Microsoft no longer provides security patches or updates for end-of-life Exchange Server versions.
Running an unpatched mail server in 2026 creates serious risks:
- No security patches for newly discovered vulnerabilities.
- Compliance audit findings for organizations subject to HIPAA, SOC 2, or CMMC.
- Increasing cost of maintaining aging on-premises infrastructure.
- Inability to access Microsoft 365 Copilot features — which require Exchange Online mailboxes.
Exchange Online: what you gain
Exchange Online is Microsoft 365's cloud-hosted email service. Moving from on-premises Exchange gives organizations:
- 99.9% uptime SLA from Microsoft.
- 50 GB per mailbox (or unlimited with E3/E5).
- Built-in Defender for Office 365 anti-phishing and anti-malware.
- Microsoft Purview compliance tools: retention, eDiscovery, audit logging.
- Microsoft 365 Copilot eligibility (requires Exchange Online mailbox).
- Elimination of on-premises mail server hardware and maintenance costs.
Frequently asked questions
When did Exchange Server 2019 reach end-of-life?
Exchange Server 2019 reached its end-of-life in October 2025. Microsoft no longer offers security updates for this version. Organizations still using Exchange Server 2019 on-premises face risks from unpatched vulnerabilities.
These risks can lead to:
- Security breaches
- Compliance audit findings
How long does an Exchange migration take?
A cutover migration, which involves fewer than 150 mailboxes, typically takes 1 to 2 weeks.
A staged migration, for 150 to 2,000 mailboxes, usually requires 4 to 8 weeks.
For a hybrid migration in a large enterprise with over 2,000 mailboxes, the process can take 8 to 16 weeks and involves a phased rollout.
What data is migrated from Exchange Server to Exchange Online?
EPC Group migrates all mailbox data, including:
- Calendar items
- Contacts
- Tasks
- Public folder content
Litigation holds, retention policies, and compliance holds transfer correctly. Mail-enabled distribution groups and shared mailboxes also migrate.
What is a hybrid Exchange deployment?
A hybrid Exchange deployment combines on-premises Exchange with Exchange Online. This setup allows users to be included in one Global Address List. Additionally, mail can flow seamlessly between on-premises and cloud mailboxes.
This setup is perfect for large organizations with over 2,000 mailboxes. It supports a phased migration timeline.
Does EPC Group provide post-migration support?
Yes. EPC Group offers 30-day hypercare support following every migration. We also provide ongoing Exchange Online managed services for organizations that need:
- Continuous monitoring
- Security patching coordination
- Quarterly compliance reviews
Plan your Exchange migration today
Talk to an EPC Group Exchange architect. Call (888) 381-9725 or request a 30-minute discovery call.
Related reading
- Exchange vs Gmail for Business
- Emergency Microsoft 365 Support: Same-Day Response from Senior Microsoft Architects
- Emergency SharePoint Support: Same-Day Response from Senior Microsoft Architects
- Anonymized engagement summary: Exchange Server 2010 to Exchange Server 2019 migration for a municipal government (2023)
Anonymized engagement summaries
EPC-reported accounts of client work. The client is not named, and supporting project records are not published in the Evidence Center, so these summaries are not part of its documented-engagement counts.
- Exchange 2010 to 2019 Migration: Municipal Government (2023) — Local government
- Exchange 2019 Hybrid Migration: Community Bank (2025) — Banking
- Exchange Online Migration: Transportation Agency (2023) — State government — transportation