Microsoft 365 / Sub-service 02
Hybrid Exchange decommission consultant.
Senior-led. Fixed-fee.
Most companies that migrated mailboxes to Exchange Online never decommissioned the on-prem Exchange server. Hybrid was 'temporary.' Five years later, it's still running. We finish the job — Hybrid Configuration Wizard removal, recipient management to Entra ID, validated mail flow, hypercare.
Exchange 2016 and 2019 — ESU Period 2 ends October 14, 2026.
Service detail
What a hybrid Exchange decommission consultant delivers
A coordinated decom that finishes what most M365 migrations skipped. Final mailbox migration, public-folder retirement, Hybrid Configuration Wizard removal, on-prem Exchange server decommission, DNS cleanup, validated mail flow, hypercare.
What's in scope
- ›Final mailbox migration to Exchange Online
- ›Public folder migration or retirement
- ›Hybrid configuration removal (HCW)
- ›On-prem Exchange server decommission
- ›Recipient management transition (Entra ID-driven)
- ›DNS cleanup (Autodiscover, MX, SPF)
- ›Documentation transfer for the operations team
Why now matters
- ›Exchange Server 2016 and 2019 reached end-of-support October 14, 2025
- ›ESU Period 2 covers May–October 2026 only
- ›After Oct 2026, no security updates available without paying penalty pricing
- ›Hybrid topology becomes a security and operations liability
- ›Most clients running hybrid have been 'temporarily' hybrid for 4+ years
What you get
- ›Written decom runbook with rollback procedures
- ›Validated mail flow before any server is touched
- ›Two weeks of hypercare post-decom
- ›Documentation for any remaining recipient-management requirements
- ›Final post-mortem and Exchange-Online-only operations handoff
FAQ
Common questions about Exchange decom.
What does a hybrid Exchange decommission consultant do?
A hybrid Exchange decommission consultant retires the on-premises Exchange server that remained after a Microsoft 365 mailbox migration. The work spans final mailbox cleanup, public-folder migration or retirement, Hybrid Configuration Wizard (HCW) removal, the on-prem Exchange Server uninstall, recipient-management transition to Entra ID, DNS cleanup (Autodiscover, MX, SPF, DKIM), validated mail-flow testing, and two weeks of hypercare. The deliverable is a written runbook with rollback procedures and a clean Exchange-Online-only operating model.
What is the Exchange Server 2019 ESU deadline?
Exchange Server 2016 and 2019 reached end-of-support on October 14, 2025. Extended Security Updates (ESU) Period 2 covers May 2026 through October 2026. After October 2026, no security updates are available without paying penalty pricing, and any unsupported on-prem Exchange becomes a security and compliance liability.
Can I keep one Exchange server for recipient management?
No longer required. Microsoft now supports Entra ID-only recipient management for hybrid customers. The 'one server for management' pattern is a 2018-era workaround. Decommissioning the last Exchange server is now fully supported and recommended.
How long does Exchange decommission typically take?
For a single-site, single-server hybrid: 4–6 weeks including discovery, parallel-run validation, decommission, DNS cleanup, and two weeks of hypercare. Multi-site Exchange Hybrid Configuration Wizard (HCW) deployments add 2–4 weeks per additional site.
What happens to public folders during decom?
Two paths: migrate to Exchange Online public folders (supported), or retire entirely and replace with Microsoft 365 Groups, Teams channels, or shared mailboxes — usually the better long-term answer. We assess the public-folder content during discovery and recommend per-folder.
Field notes
- → Exchange Server 2019 EOL: your real migration deadline — the four real migration paths and the cost of staying past Oct 14, 2025.
Stuck in hybrid for years? Let's get you out.
Tell us your Exchange version and mailbox count. Two-business-day response with scope and a fixed-fee range.