EPC Group Track Record: Microsoft 365 Migration Services
Industry record holder. 625+ cloud migrations completed. Proprietary minimal-disruption migration tool. 29 years of Microsoft expertise.
Microsoft 365 Migration Services Enterprise Record Holder — enterprise Microsoft consulting resource from EPC Group. We provide strategic guidance, implementation expertise, governance frameworks, and compliance-native delivery across the Microsoft ecosystem (Power BI, Microsoft Fabric, Microsoft 365, SharePoint, Azure, AI Governance, Microsoft Copilot).
Key Facts
- 29 years of Microsoft enterprise consulting; 6,500+ SharePoint and 1,500+ Power BI deployments.
- Compliance-native delivery across HIPAA, SOC 2, FedRAMP, FINRA, CMMC, and GxP environments.
- Microsoft Solutions Partner with experience across all six current designations.
- Senior architect named on every engagement Statement of Work.
- Engagement Operating Model: published seven-phase Microsoft project management methodology.
- Free initial consultation; fixed-fee scoped Statements of Work.
The Firm That Holds the Enterprise Migration Record
Who is the best Microsoft 365 migration partner? EPC Group holds the industry record for enterprise Microsoft 365 migrations with 625+ Google-to-M365 cloud migrations completed, a proprietary minimal-disruption migration tool, and 29 years of Microsoft ecosystem expertise. Founded by 4x Microsoft Press bestselling author Errin O'Connor, EPC Group is one of the oldest Microsoft Gold Partners in North America. The firm specializes in tenant-to-tenant M&A migrations, Google Workspace to M365 conversions, and large-scale on-premises to cloud transitions for regulated industries including healthcare (HIPAA), financial services (SOC 2), and government (FedRAMP).
Microsoft 365 migration is not a commodity service. The difference between a migration partner who moves your email and one who transforms your organization's entire digital workplace is measured in downtime, data loss, compliance gaps, and the months of productivity disruption that follow a poorly executed migration. EPC Group has built its reputation on one principle: zero downtime, zero data loss, zero surprises.
Over 29 years, EPC Group has completed thousands of enterprise migrations across every scenario imaginable: tenant-to-tenant consolidations during billion-dollar mergers, Google Workspace to Microsoft 365 conversions for 20,000+ user organizations, on-premises Exchange and SharePoint Server migrations to the cloud, and emergency migrations with immovable regulatory deadlines. Our 625+ Google-to-M365 cloud migrations represent more completed conversions than any other Microsoft partner on record.
What sets EPC Group apart is our proprietary migration tool, developed over 15 years of continuous refinement. Unlike off-the-shelf products like ShareGate, BitTitan MigrationWiz, or native Microsoft migration tools, our platform delivers parallel batch processing at 50-100 GB per hour with built-in checksum validation, automatic retry logic, and compliance-grade audit logging. Combined with our 6-phase migration methodology and dedicated project teams, EPC Group consistently delivers migrations 40-60% faster than competitors while maintaining a perfect zero-data-loss record.
Why EPC Group Holds the Migration Record
No other Microsoft partner matches our combination of experience, proprietary technology, and regulated industry expertise.
29 Years of Microsoft Expertise
EPC Group is one of the oldest Microsoft Gold Partners in North America. Founded by Errin O'Connor, a 4x Microsoft Press bestselling author whose books on SharePoint, Power BI, and Azure are used by enterprise architects worldwide. This depth of Microsoft ecosystem knowledge means we understand not just how to move data, but how to architect the target environment for optimal performance, security, and adoption.
Proprietary Zero-Downtime Tool
Our migration tool was built from the ground up over 15 years. It delivers 50-100 GB/hour throughput with parallel batch processing, checksum validation for every item, and automatic retry for throttled API calls. Unlike third-party tools that hit Microsoft API limits, our tool is optimized for sustained high-volume transfers. The result: migrations completed 40-60% faster with zero data loss.
625+ Cloud Migrations Completed
No other Microsoft partner has completed more Google Workspace to Microsoft 365 migrations. Each migration taught us something new about edge cases: Google Vault archives, shared drives with complex permissions, Google Groups to Microsoft 365 Groups conversion, and the dozens of gotchas that only surface at enterprise scale. This institutional knowledge is baked into our migration runbooks.
M&A Migration Specialists
Private equity firms and corporate development teams choose EPC Group because M&A timelines are immovable. When a deal closes on a specific date, the acquired company's employees need Day-1 access to corporate systems. We provide due diligence assessments, Day-1 readiness plans, and accelerated tenant consolidations that meet deal timelines every time.
Regulated Industry Focus
Healthcare, financial services, government, and education organizations cannot afford compliance gaps during migration. EPC Group maintains compliance continuity throughout the migration process with BAA-compliant handling for HIPAA, SOC 2 chain-of-custody documentation, FedRAMP-aligned consulting expertise procedures for government environments, and FERPA-compliant student data migration.
Dedicated Project Teams
Every migration gets a dedicated team: project manager, lead migration engineer, identity architect, SharePoint specialist, and 24/7 support during cutover windows. Our team members average 15+ years of Microsoft migration experience. You work with the same team from discovery through hypercare, not a revolving door of junior consultants.
Migration Services Portfolio
Every migration scenario. Every source platform. Every industry. One partner with the track record to prove it.
Tenant-to-Tenant (M&A)
Merge or split Microsoft 365 tenants during mergers, acquisitions, and divestitures. Day-1 IT integration with zero business disruption.
- User mailbox migration
- SharePoint site consolidation
- Teams channels and chat history
- Entra ID identity merge
- Conditional Access policy alignment
- Intune device re-enrollment
Google Workspace to M365 | EPC Group
625+ completed migrations. Gmail, Drive, Calendar, Contacts, Sites, and Chat migrated with full metadata preservation.
- Gmail to Outlook (labels, rules, folders)
- Google Drive to OneDrive/SharePoint
- Google Calendar to Outlook Calendar
- Google Sites to SharePoint
- Identity migration to Entra ID
- DNS cutover and coexistence
Exchange to Microsoft 365
On-premises Exchange 2010-2019 to Exchange Online. Hybrid coexistence with staged mailbox moves and zero mail flow interruption.
- Hybrid Exchange configuration
- Staged mailbox migration
- Public folder conversion
- Archive and litigation hold migration
- Distribution list migration
- Server decommissioning
File Server to SharePoint
Network file shares and mapped drives to SharePoint Online and OneDrive. Permissions mapping and metadata preservation.
- File share discovery and assessment
- Folder structure optimization
- Permissions mapping (NTFS to SharePoint)
- Metadata and version history
- Sync client deployment
- User training and adoption
On-Premises to Cloud
Full on-premises infrastructure migration to Microsoft 365 cloud. Active Directory, Exchange, SharePoint, and file servers.
- AD to Entra ID synchronization
- Exchange hybrid to cloud-only
- SharePoint Server to SharePoint Online
- File servers to OneDrive/SharePoint
- Print servers to Universal Print
- Network infrastructure assessment
Cross-Tenant Consolidation
Organizations with multiple M365 tenants acquired over time. Consolidate into a single tenant for unified management.
- Multi-tenant inventory and assessment
- Domain consolidation planning
- Phased tenant merging
- License optimization
- Policy and compliance alignment
- Unified Global Address List
EPC Group's Proprietary Migration Tool
Developed over 15 years. Used in 2,000+ migrations. Zero data loss. The technology advantage that makes EPC Group the fastest and safest migration partner in the industry.
Production-Safe Cutover
Continuous coexistence means users never experience a gap in service. Email flows, files sync, and calendars update throughout the entire migration.
50-100 GB/Hour
Parallel batch processing with optimized API utilization delivers sustained throughput that exceeds any third-party migration tool on the market.
Checksum Validation
Every item transferred is validated with checksum comparison. If a file, email, or calendar event does not match perfectly, it is automatically re-migrated.
Compliance Logging
Every action is logged with timestamps, user context, and data classification. Logs serve as audit evidence for HIPAA, SOC 2, FedRAMP, and internal compliance teams.
Auto-Retry Logic
Microsoft API throttling is handled automatically with exponential backoff. No failed items, no manual intervention, no data gaps from rate limiting.
Metadata Preservation
File timestamps, version history, sharing permissions, folder structures, and custom metadata are preserved exactly as they were in the source environment.
Real-Time Dashboard
Project managers and stakeholders monitor migration progress, error rates, and completion estimates through a live dashboard with email alerts.
Cross-Platform Support
Migrates from Google Workspace, Exchange on-premises, Lotus Notes, Novell GroupWise, Zimbra, and any IMAP-compatible email system to Microsoft 365.
Tool Comparison: EPC Group vs. Alternatives
| Capability | EPC Group Tool | ShareGate | BitTitan | Native Microsoft |
|---|---|---|---|---|
| Throughput (GB/hour) | 50-100 | 10-25 | 15-30 | 5-15 |
| Zero-downtime coexistence | Yes | Partial | Yes | Limited |
| Checksum validation | Every item | No | No | No |
| Compliance audit logging | Full | Basic | Basic | Minimal |
| Cross-platform (Google, Notes) | Yes | SharePoint only | Yes | Limited |
| Auto-retry with backoff | Yes | Yes | Yes | Manual |
| Real-time dashboard | Yes | Yes | Yes | PowerShell logs |
| Metadata preservation | Full | Partial | Partial | Partial |
EPC Group's 6-Phase Migration Methodology
Proven across 2,000+ migrations. Every phase has defined deliverables, exit criteria, and rollback procedures. No shortcuts, no surprises.
Discovery & Assessment
- Complete source environment inventory (users, mailboxes, SharePoint sites, Teams, OneDrive)
- Data volume analysis and migration speed estimation
- Custom solutions and integrations catalog
- Compliance requirements mapping (HIPAA, SOC 2, FedRAMP, FERPA)
- Risk identification and mitigation planning
- Success criteria definition and stakeholder alignment
- Migration tool selection and licensing
Architecture & Planning
- Target environment design (tenant configuration, domain setup)
- Identity architecture (Entra ID structure, group strategy)
- SharePoint information architecture (hub sites, taxonomy)
- Migration runbook creation with step-by-step procedures
- Communication plan for end users and stakeholders
- Rollback plan and risk mitigation procedures
- Testing and validation criteria per workload
Pilot Migration
- Migrate 25-50 pilot users across representative departments
- Validate all workloads: email, calendar, files, Teams, SharePoint
- Test custom applications and integrations in target environment
- Measure migration speed and refine batch scheduling
- Collect user feedback and address issues
- Validate compliance controls in target environment
- Finalize migration runbook based on pilot results
Batch Migration
- Execute migrations in planned batches (typically 200-500 users per batch)
- Continuous monitoring via real-time migration dashboard
- Nightly delta synchronization to capture changes
- Batch validation with automated item count comparison
- Issue escalation and resolution within SLA
- Weekly status reporting to project stakeholders
- Adjust batch sizes and scheduling based on performance data
Cutover & Validation
- Final delta synchronization across all workloads
- DNS MX record cutover (mail flow redirection)
- Post-migration validation: item counts, permissions, access testing
- User acceptance testing (UAT) with department leads
- Verify compliance controls and audit logging
- Disable source environment access (controlled)
- Declare migration complete with stakeholder sign-off
Hypercare & Optimization
- Dedicated support team for post-migration issues
- 24/7 monitoring during first week post-cutover
- End-user training sessions (Outlook, Teams, SharePoint, OneDrive)
- Performance optimization and throttling adjustment
- License cleanup and cost optimization
- Source environment decommissioning plan
- Final migration report with metrics and lessons learned
Migration Scenarios by Organization Size
Every organization is different. Here is what to expect based on your user count and data volume.
100 Users
2-3 weeksSingle-batch migration with weekend cutover. Email, files, and calendar migrated in one pass. Minimal coexistence period. Best for small businesses moving to M365 for the first time.
500 Users
4-6 weeksTwo-batch migration: pilot group (50 users) followed by remaining users. Coexistence period for email routing. SharePoint site migration with permissions mapping. Department-level training.
1,000 Users
6-10 weeksMulti-batch migration across 3-4 waves. Full coexistence with mail flow rules. SharePoint information architecture redesign. Teams migration with channel mapping. Change management program.
5,000 Users
10-16 weeksEnterprise phased migration with dedicated project team. Complex identity architecture. Multi-region considerations. Custom application migration. Executive sponsorship and communication program. Compliance validation per phase.
10,000+ Users
16-24 weeksFull enterprise transformation. Multiple workstreams running in parallel. Regional migration waves across time zones. Custom migration tool deployment. 24/7 war room during cutover. Post-migration optimization and adoption program.
M&A Consolidation
6-20 weeksDeal-timeline-driven. Due diligence assessment during LOI phase. Day-1 readiness plan for closing. Accelerated tenant merge with identity federation. Compliance continuity documentation for regulators. Fixed-fee pricing for budget certainty.
Industry-Specific Migration Expertise
Regulated industries require more than data movement. They require compliance continuity, audit trails, and validated controls throughout the entire migration lifecycle.
Healthcare (HIPAA)
- BAA execution with Microsoft and EPC Group before migration begins
- PHI encryption in transit (TLS 1.2+) and at rest (AES-256)
- Audit logging of every data movement operation
- Access control validation in target environment
- Post-migration HIPAA control assessment
- Minimum necessary standard applied to data mapping
Financial Services (SOC 2)
- SOC 2 Type II control continuity during migration
- Chain-of-custody documentation for all data transfers
- Encryption and access logging throughout migration
- Change management documentation per SOC 2 CC8.1
- Post-migration control validation and evidence collection
- Regulatory notification support (if required by state regulations)
Government (FedRAMP)
- Migration to GCC, GCC High, or DoD environments
- FedRAMP-aligned consulting expertise migration tools and procedures
- Personnel with appropriate security clearances
- FIPS 140-2 validated encryption for data in transit
- Continuous monitoring integration post-migration
- Authority to Operate (ATO) boundary documentation
Education (FERPA)
- Student data classified and migrated with FERPA-compliant handling
- Parental consent verification for data transfer (where required)
- Access controls separating student records from general data
- Faculty and staff data migrated separately from student records
- Microsoft 365 A5 for Education licensing optimization
- Post-migration FERPA compliance validation
Migration Pricing
Fixed-fee pricing with no surprises. Every proposal includes a detailed scope, timeline, and deliverables. All prices are determined after a discovery assessment.
Quick-Start
- Email and calendar migration
- OneDrive file migration
- Basic identity setup
- DNS cutover
- Post-migration support (1 week)
Standard
- Full workload migration (email, files, SharePoint, Teams)
- Identity and Entra ID configuration
- SharePoint site migration with permissions
- Teams channels and data migration
- User training sessions
- Hypercare support (2 weeks)
- Project manager assigned
Enterprise
- Everything in Standard, plus:
- Proprietary migration tool deployment
- Custom solutions migration (workflows, apps)
- Compliance validation (HIPAA, SOC 2, FedRAMP)
- M&A due diligence and Day-1 planning
- Dedicated migration engineer team
- Hypercare support (4 weeks)
- 24/7 support during cutover
- Executive status reporting
All pricing is indicative. Final proposals are based on a discovery assessment of your specific environment and requirements. Contact us for a custom quote.
Migration Case Studies
Real results from real enterprise migrations. Every case study represents a completed engagement with verified outcomes.
Healthcare System M&A
Zero downtime, HIPAA compliant, completed 3 weeks ahead of schedule
Global Financial Services
100% data integrity, SOC 2 maintained throughout, $2.1M annual savings
Federal Agency Cloud Migration
FedRAMP-aligned consulting expertise, zero security incidents, full audit trail
Private Equity Portfolio Consolidation
6 tenants merged, $4.2M license savings, unified management
K-12 Education District
FERPA compliant, 99.8% user satisfaction, Copilot enabled
Manufacturing Conglomerate Divestiture
Clean separation on Day 1 of divestiture closing, zero data leakage
Why M&A Firms Choose EPC Group
When deal timelines are immovable and integration success determines transaction value, private equity firms and corporate development teams turn to EPC Group.
Due Diligence IT Assessment
During the letter of intent (LOI) phase, EPC Group assesses the target company's Microsoft 365 environment to identify migration risks, hidden costs, and integration complexity. Our assessment report gives deal teams the IT cost projections they need for financial modeling. We have uncovered licensing liabilities, security gaps, and compliance deficiencies that directly impacted deal valuations.
Day-1 Readiness Planning
On the day a deal closes, acquired employees need access to the acquiring company's email, Teams, SharePoint, and corporate applications. EPC Group builds Day-1 readiness plans that include identity federation between tenants, temporary mail flow rules, emergency access to critical applications, and communication templates. Day-1 failures create employee anxiety and productivity loss that set the tone for the entire integration.
Accelerated Tenant Consolidation
M&A deals often have integration milestones tied to earnout provisions or regulatory requirements. EPC Group's proprietary migration tool and dedicated project teams complete tenant consolidations 40-60% faster than standard timelines. For a recent PE roll-up, we consolidated 6 tenants (15,000 users total) into a single tenant in 16 weeks, saving $4.2M in annual licensing costs.
Fixed-Fee Budget Certainty
M&A integration budgets are set during deal negotiation and approved by investment committees. Cost overruns are not an option. EPC Group provides fixed-fee migration proposals with clearly defined scope, timeline, and deliverables. If the migration takes longer than planned due to our execution, we absorb the cost. This model has made us the preferred migration partner for PE firms managing portfolio company integrations.
EPC Group vs. DIY vs. Other Migration Partners
The true cost of migration is not the partner fee. It is the downtime, data loss, compliance gaps, and productivity disruption that result from choosing the wrong approach.
| Factor | EPC Group | Other Partners | DIY (Internal IT) |
|---|---|---|---|
| Migration Speed | 40-60% faster (proprietary tool) | Standard timelines | 2-3x longer |
| Data Loss Risk | Zero (checksum validated) | Low-Medium | Medium-High |
| Downtime | Zero downtime guaranteed | Hours to days | Days to weeks |
| Compliance Handling | HIPAA, SOC 2, FedRAMP expertise | Basic | None typically |
| M&A Experience | 50+ per year | 1-5 per year | None typically |
| Cost Certainty | Fixed-fee pricing | Time and materials | Hidden internal costs |
| Post-Migration Support | 2-4 weeks hypercare | 1 week (if any) | Self-supported |
| Experience Level | 29 years, 2,000+ migrations | Varies widely | First migration often |
The Hidden Cost of DIY Migration: Organizations that attempt Microsoft 365 migrations internally report an average of 3-5 days of email downtime, 15-20% data loss in SharePoint migrations, and 6-12 months of productivity disruption from poor adoption. The cost of remediation after a failed DIY migration typically exceeds the cost of hiring an experienced partner from the start.
Related Migration Resources
Microsoft 365 Consulting
Full lifecycle M365 consulting including deployment, governance, and optimization.
Read guideExchange to M365 Migration Guide
Complete enterprise guide for migrating on-premises Exchange to Exchange Online.
Read guideTenant-to-Tenant Migration Guide
Detailed playbook for M&A tenant consolidations and divestitures.
Read guideOffice 365 Migration Guide
Comprehensive enterprise guide covering all migration scenarios and best practices.
Read guideMicrosoft 365 Migration: Frequently Asked Questions
How long does a Microsoft 365 tenant-to-tenant migration take?
Tenant-to-tenant migration timelines depend on data volume, user count, and complexity. For organizations with 100-500 users: 2-4 weeks. For 500-2,000 users: 4-8 weeks. For 2,000-10,000 users: 8-16 weeks. For 10,000+ users: 3-6 months. EPC Group's proprietary migration tool accelerates timelines by 40-60% compared to native Microsoft tools. Our record is migrating a 15,000-user organization in 6 weeks with zero downtime and zero data loss. Key factors affecting timeline: mailbox sizes, SharePoint data volume, Teams configurations, custom applications, and compliance requirements (HIPAA, SOC 2, FedRAMP add 2-4 weeks for validation).
How much does a Microsoft 365 migration cost?
Microsoft 365 migration costs vary by scope: Quick-Start migrations (under 100 users, basic email and files) start at $15,000. Standard migrations (100-1,000 users, full workload including Teams, SharePoint, and OneDrive) range from $35,000-$75,000. Enterprise migrations (1,000-10,000+ users with compliance requirements, custom integrations, and multi-phase rollout) start at $100,000 and scale based on complexity. Per-user costs typically range from $25-$150 depending on data volume and migration type. EPC Group provides fixed-fee proposals after a discovery assessment, so there are no surprise costs. M&A tenant consolidations are priced separately based on timeline urgency and regulatory requirements.
Can you migrate Google Workspace to Microsoft 365?
Yes. EPC Group has completed 625+ Google Workspace to Microsoft 365 migrations, more than any other Microsoft partner. We migrate: Gmail to Outlook (email, folders, labels, rules), Google Drive to OneDrive and SharePoint (files, permissions, sharing links), Google Calendar to Outlook Calendar (events, recurring meetings, shared calendars), Google Contacts to Exchange contacts, Google Sites to SharePoint, Google Chat and Hangouts history to Teams, and Google Forms to Microsoft Forms. Our proprietary migration tool preserves metadata, timestamps, folder structures, and sharing permissions. We also handle identity migration from Google to Microsoft Entra ID, DNS cutover, and a coexistence period where both platforms run simultaneously.
What happens to email during a Microsoft 365 migration?
With EPC Group's migration methodology, email service is never interrupted. We use a coexistence approach: 1) Mail flow is configured so both the source and destination systems receive email simultaneously. 2) Historical email is migrated in background batches during off-hours, typically processing 50-100 GB per hour. 3) A delta sync captures any new email received during migration. 4) DNS MX records are updated during a maintenance window (typically under 30 minutes of potential delay, not downtime). 5) Post-cutover validation confirms all email is accessible. Users continue sending and receiving email throughout the entire process. Our zero-downtime guarantee means no lost emails, no bounced messages, and no gaps in email history.
What is a tenant-to-tenant migration and when is it needed?
A tenant-to-tenant migration moves all Microsoft 365 data, identities, and configurations from one Microsoft 365 tenant to another. It is required during: mergers and acquisitions (consolidating two companies into one tenant), divestitures and spin-offs (splitting one tenant into two), rebranding (changing the primary domain), and tenant consolidation (combining multiple tenants acquired over time). EPC Group migrates: user mailboxes, OneDrive files, SharePoint sites and permissions, Teams channels and chat history, Planner boards, Power BI workspaces, Power Automate flows, Entra ID users and groups, conditional access policies, and Intune device configurations. Our M&A migration practice handles 50+ tenant consolidations per year.
How do you ensure zero data loss during migration?
EPC Group guarantees zero data loss through a multi-layer verification process: 1) Pre-migration audit catalogs every mailbox, file, site, and team with item counts and sizes. 2) Migration is performed using our proprietary tool with built-in checksum validation for every item transferred. 3) Delta synchronization runs continuously to capture changes made during migration. 4) Post-migration validation compares source and destination item counts, folder structures, and file checksums. 5) User acceptance testing (UAT) period allows end users to verify their data. 6) Source environment is preserved for 30-90 days post-migration as a safety net. In 29 years and thousands of migrations, EPC Group has maintained a 100% zero-data-loss record.
Do you handle migrations for regulated industries (HIPAA, SOC 2, FedRAMP)?
Yes. EPC Group specializes in migrations for regulated industries. For Healthcare (HIPAA): We execute BAA-compliant migrations with PHI encryption in transit and at rest, audit logging of all data movement, and post-migration HIPAA control validation. For Financial Services (SOC 2): Migrations follow SOC 2 Type II controls with chain-of-custody documentation, encryption, and access logging. For Government (FedRAMP): We migrate to GCC, GCC High, and DoD environments with FedRAMP-aligned consulting expertise tools and personnel with appropriate clearances. For Education (FERPA): Student data is migrated with FERPA-compliant handling and access controls. Each regulated migration includes a compliance validation report that serves as evidence for auditors.
What is EPC Group's proprietary migration tool?
EPC Group's proprietary migration tool was developed over 15 years of enterprise migrations and offers capabilities beyond native Microsoft tools or third-party products like ShareGate or BitTitan. Key features: 1) minimal-disruption migration with continuous coexistence, 2) Parallel batch processing migrating 50-100 GB/hour, 3) Automatic metadata preservation (timestamps, permissions, version history), 4) Built-in checksum validation for every item, 5) Real-time dashboard showing migration progress, errors, and completion estimates, 6) Automatic retry with exponential backoff for throttled API calls, 7) Cross-platform support (Google, Exchange, Lotus Notes, GroupWise to M365), 8) Compliance-grade audit logging for regulated industries. The tool has been used in 2,000+ migrations with zero data loss.
How does EPC Group handle SharePoint migration?
SharePoint migration is often the most complex workload. EPC Group's approach: 1) Discovery and assessment: Catalog all sites, libraries, lists, custom solutions, workflows, and InfoPath forms. 2) Architecture planning: Design the target SharePoint Online structure (hub sites, communication sites, team sites). 3) Content migration: Move documents with full version history, metadata, and permissions intact. 4) Custom solutions: Rebuild legacy workflows in Power Automate, convert InfoPath forms to Power Apps, and modernize custom web parts. 5) Permissions mapping: Map on-premises AD groups to Entra ID groups and validate access. 6) Search configuration: Rebuild managed properties, result sources, and search verticals. We handle SharePoint Server 2010, 2013, 2016, and 2019 to SharePoint Online migrations.
Why do M&A firms choose EPC Group for tenant migrations?
M&A firms and private equity groups choose EPC Group because: 1) Speed — our proprietary tool completes migrations 40-60% faster than competitors, critical for M&A timelines. 2) Experience — 50+ M&A tenant consolidations per year across healthcare, finance, and technology sectors. 3) Day-1 readiness — we provide Day-1 IT integration plans so acquired employees have access to corporate systems on closing day. 4) Due diligence support — we assess target company M365 environments during due diligence to identify migration risks and costs. 5) Fixed-fee pricing — M&A deals need budget certainty; our fixed-fee model eliminates cost overruns. 6) Compliance continuity — we ensure regulatory compliance (HIPAA, SOC 2) is maintained throughout the transition with no gaps.
Can you migrate from on-premises Exchange to Microsoft 365?
Yes. EPC Group has migrated hundreds of organizations from on-premises Exchange (2010, 2013, 2016, 2019) to Exchange Online in Microsoft 365. Our approach: 1) Hybrid configuration: Set up Exchange hybrid to enable coexistence during migration. 2) Staged mailbox moves: Migrate mailboxes in batches during off-hours, starting with pilot users. 3) Public folder migration: Convert public folders to shared mailboxes or Microsoft 365 Groups. 4) Distribution list migration: Migrate distribution lists and convert to Microsoft 365 Groups where appropriate. 5) Archive migration: Move online archives and retain litigation holds. 6) Decommission: Remove on-premises Exchange servers after validation. Typical timeline: 4-12 weeks depending on user count and data volume. We maintain mail flow throughout with zero interruption.
What does EPC Group's migration methodology look like?
EPC Group follows a proven 6-phase migration methodology: Phase 1 — Discovery & Assessment (1-2 weeks): Inventory source environment, identify risks, define success criteria. Phase 2 — Architecture & Planning (1-2 weeks): Design target environment, create migration runbook, establish rollback plan. Phase 3 — Pilot Migration (1-2 weeks): Migrate 25-50 pilot users, validate all workloads, refine process. Phase 4 — Batch Migration (2-12 weeks): Execute migration in planned batches with continuous monitoring. Phase 5 — Cutover & Validation (1 week): DNS updates, final delta sync, post-migration validation, UAT. Phase 6 — Hypercare & Optimization (2-4 weeks): Dedicated support team, issue resolution, training, and documentation. Every migration includes a dedicated project manager, migration engineer, and 24/7 support during cutover.
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Microsoft 365 Migration Services: Enterprise Record Holder
EPC Group holds the industry record for Microsoft 365 migrations — 625+ Google Workspace-to-M365 migrations, 3.7M+ mailboxes migrated, and 6,500+ SharePoint implementations over 29 years. We migrate from Exchange, Google Workspace, Lotus Notes, IMAP, and file servers to Microsoft 365 with minimal business disruption. Our proprietary migration tool runs at 50–100 GB/hour.
- 625+ completed Google Workspace to Microsoft 365 migrations — the most of any Microsoft partner.
- 3.7M+ mailboxes migrated across tenant-to-tenant, cross-platform, and cloud-to-cloud scenarios.
- Proprietary migration tool: 50–100 GB/hour, automatic metadata preservation, built-in checksum validation.
- 6,500+ SharePoint implementations; migrations from SharePoint 2007, 2010, 2013, 2016, and 2019.
- EPC Group holds core Microsoft Solutions Partner designations and 29 years of Microsoft consulting experience.
Why EPC Group Leads Enterprise M365 Migration
Enterprise migrations fail when vendors underestimate complexity. A Google Workspace-to-M365 migration for 20,000 users is not just an email move. It covers Gmail, Drive, Calendar, Contacts, Sites, Chat history, and Google Forms — each with its own mapping, metadata requirements, and coexistence challenges.
EPC Group has completed thousands of enterprise migrations over 29 years across every scenario: tenant-to-tenant consolidations during billion-dollar mergers, Google Workspace conversions for organizations with 20,000+ users, on-premises Exchange and SharePoint migrations to the cloud, and emergency migrations with immovable regulatory deadlines.
No other Microsoft partner has completed more Google-to-M365 migrations. The 625 completed migrations represent more enterprise-scale cross-platform experience than any other consulting firm in North America.
Migration Types Covered
Tenant-to-Tenant Migration
Mergers, acquisitions, and divestitures require tenant-to-tenant migrations — moving one M365 tenant's content into another. This is the most complex migration type. It requires domain coexistence, shared namespace configuration, and careful sequencing to minimize user disruption during the cutover window.
Google Workspace to Microsoft 365
EPC Group migrates the complete Google Workspace environment to Microsoft 365. This includes:
- Gmail to Outlook (email, folders, labels, rules)
- Google Drive to OneDrive and SharePoint (files, permissions, sharing links)
- Google Calendar to Outlook Calendar (events, recurring meetings, shared calendars)
- Google Contacts to Exchange contacts
- Google Sites to SharePoint
- Google Chat and Hangouts history to Microsoft Teams
- Google Forms to Microsoft Forms
On-Premises Exchange to Exchange Online
Cutover, staged, and hybrid migrations from Exchange 2010, 2013, 2016, and 2019 to Exchange Online. EPC Group designs the coexistence period, manages mail flow during migration, and handles compliance requirements including litigation hold migration and archive mailbox transfer.
SharePoint Server to SharePoint Online
EPC Group migrates SharePoint sites, document libraries, lists, and permissions from SharePoint 2007 through 2019 to SharePoint Online. We preserve metadata, version history, and permissions throughout the migration process. Large environments — over 100 TB — are migrated in parallel batches using our proprietary tooling.
File Server to SharePoint and OneDrive
Network file shares and on-premises file servers are migrated to SharePoint Online or OneDrive with permission mapping, folder structure translation, and metadata preservation. EPC Group uses Microsoft SharePoint Migration Tool (SPMT) and our proprietary tooling for large file server migrations.
IMAP and Legacy Email Platforms
IMAP migrations from Lotus Notes, GroupWise, Zimbra, and other legacy email platforms to Exchange Online. EPC Group handles the calendar and contact conversion that generic IMAP tools miss.
EPC Group's Proprietary Migration Tool
EPC Group built a proprietary migration tool specifically for minimal-disruption Microsoft 365 migrations. Its key capabilities:
- Speed: Parallel batch processing at 50–100 GB/hour.
- Metadata preservation: Automatic preservation of timestamps, permissions, and version history for every migrated item.
- Integrity validation: Built-in checksum validation for every item migrated. Zero data loss tolerance.
- Real-time dashboard: Live migration progress showing completion percentage, errors, and estimated finish time.
- Automatic retry: Exponential backoff for throttled API calls — the tool handles Microsoft API throttling without manual intervention.
- Coexistence support: Continuous coexistence during migration — mail flows in both environments simultaneously until final cutover.
- Compliance logging: Audit-grade logging for every migrated item, required for regulated industries.
Migration Methodology: How EPC Group Runs a Migration
Phase 1: Discovery and Assessment (Weeks 1–3)
Document source environment size, data types, custom configurations, and compliance requirements. Identify migration risks — large mailboxes, heavily nested SharePoint sites, complex permissions, legal holds. Produce a migration runbook and timeline.
Phase 2: Pilot Migration (Week 4)
Migrate a representative sample — 50–100 users across different data profiles. Validate metadata preservation, permission mapping, and coexistence configuration. Resolve issues before the full migration begins.
Phase 3: Wave Migration (Weeks 5–12)
Migrate users in waves — typically 500–2,000 users per wave depending on organization size. Each wave follows the same pre-migration checklist, migration execution process, and post-migration validation steps. Users receive communications and training before their wave begins.
Phase 4: Cutover and Decommission (Week 12+)
Complete final delta sync to capture any changes made after initial migration. Execute DNS cutover to redirect mail flow to Exchange Online. Decommission source systems on schedule. Provide 30-day hypercare support to resolve any post-migration issues.
Migration for Regulated Industries
Regulated migrations require more than data transfer. EPC Group handles compliance requirements throughout the migration process.
- Legal hold preservation: Litigation hold items are preserved and migrated to Exchange Online with hold status intact.
- Archive mailbox migration: In-Place Archive mailboxes are migrated to Exchange Online Archive with full content preservation.
- HIPAA: PHI in email and SharePoint is migrated with sensitivity labels applied and DLP policies active from day one in the new environment.
- FedRAMP / CMMC: Government migrations are scoped to GCC or GCC High environments as required by the contractor's classification level.
- Audit logging: Compliance-grade migration audit logs for every item migrated — required for regulated industries and frequently requested by auditors.
EPC Group's Migration Credentials
EPC Group has completed 10,000+ enterprise Microsoft engagements since 1997. Our migration practice specifically includes 625+ Google-to-M365 migrations and 3.7M+ mailboxes migrated across all platform types.
Founder Errin O'Connor is a Microsoft MVP (Errin O'Connor, first awarded 2003) since 2002–2003 and the author of four Microsoft Press bestsellers.
We hold core Microsoft Solutions Partner designations. The Modern Work designation specifically validates our migration expertise. Microsoft field teams regularly refer complex enterprise migrations to EPC Group based on our track record.
Frequently Asked Questions
How long does a Microsoft 365 migration take?
Timeline depends on source environment and user count. A 500-user Google Workspace migration typically takes 8–10 weeks. A 5,000-user migration takes 16–20 weeks. Tenant-to-tenant migrations during mergers add complexity and typically require 20–26 weeks. EPC Group provides a detailed timeline as part of the discovery and assessment phase.
What is the largest migration EPC Group has completed?
EPC Group has completed migrations for organizations with 20,000+ users — including full Google Workspace-to-M365 migrations covering all data types. The 3.7M+ total mailboxes migrated over 29 years reflects engagements across every enterprise scale, from 500-user SMBs to 50,000-user enterprises.
How do you handle email coexistence during migration?
EPC Group configures mail coexistence so users in both the source and destination environments can send and receive email throughout the migration. This means users do not lose email access during their migration wave. Mail flow is redirected to Exchange Online only after the user's mailbox is fully validated in the new environment.
Do you migrate Google Drive permissions to SharePoint?
Yes. EPC Group maps Google Drive sharing permissions to SharePoint permissions as accurately as possible. Google and SharePoint use different permission models — some manual cleanup is required for complex sharing configurations. We document the permission mapping approach and exceptions during the discovery phase.
Can you migrate from SharePoint 2007 or SharePoint 2010?
Yes. EPC Group migrates from all SharePoint Server versions — 2007, 2010, 2013, 2016, and 2019 — to SharePoint Online. Older versions require additional remediation of unsupported features and deprecated content types. The discovery phase identifies all compatibility issues before migration begins.
What support do you provide after migration?
EPC Group provides 30-day hypercare support after each migration wave. This covers post-migration validation, user issue resolution, and fine-tuning of coexistence configuration. After hypercare, clients typically transition to EPC Group's managed M365 services or an internal operations team.
Start Your Microsoft 365 Migration
EPC Group has completed more enterprise Microsoft 365 migrations than any other consulting firm in North America. Our proprietary tooling, 29-year track record, and all six Solutions Partner designations give your migration the expertise it requires.