Client: CJBS, LLC | Industry: Accounting
CJBS, a leading accounting firm in the northern suburbs of Chicago, needed to migrate their email from an on-premise Exchange Server to Office 365 Hosted Exchange — a full cloud migration project.
The Challenge
- Migrate a 2007 Microsoft Exchange Server to Office 365 Hosted Exchange while keeping the firm’s internal Active Directory infrastructure intact, requiring a hybrid cloud/on-premise setup.
- Move 50+ users’ mailboxes, folders, contacts, calendars, and tasks accumulated over 10 years without losing any data.
- Cut over on a weekend so staff could return Monday with minimal disruption.
- Decommission the old Exchange server without losing any data, admin functions, or network functionality.
The Solution
- Set up all Office 365 email services in advance, verified the domain, and pre-migrated the bulk of mailboxes, contacts, and calendars ahead of the cutover.
- Delivered clear documentation to every user explaining what was changing and how to reconnect their accounts.
- Executed the hard cutover on a Sunday, updating MX records and DNS to route mail to the new system.
- Ran a final migration pass, verified every mailbox by size, and had staff on-site Monday morning to confirm everyone was connected.
- Provided a full week of dedicated support before decommissioning the old Exchange server.
The Results
CJBS successfully migrated all email data and services to Office 365 Hosted Exchange while maintaining internal Active Directory functionality — with no lost data and zero downtime.