Microsoft365

Migrating a single Accounts Payable mailbox from Google Workspace to Exchange Online should have been the easy part of a larger phased migration. It wasn’t. The mailbox was 100GB+ with 600,000+ items, which put it past Exchange Online’s standard migration path and into Large Archive Onboarding (LAO) territory. LAO is the only supported mechanism for migrating a mailbox this size from Gmail while splitting content between primary and archive by date or folder. ...

Two weeks into a Google Workspace to Microsoft 365 pilot migration for a mid-size org. Thirteen mailboxes in the pilot batch. What should have been a straightforward cutover turned into a deep education in Exchange migration edge cases, MRS throttling behavior, and the gap between what Microsoft documents and what actually happens in production. The Setup The architecture: phased cutover with Mimecast coexistence routing, GAM-managed forwarding during the transition window, and batch migration via Exchange Online migration endpoints backed by a GCP service account. A verified alias subdomain (o365.[domain]) serves as the target delivery domain, with workspace.[domain] as the coexistence routing domain pointing back to Google. ...

Most migration guides describe the happy path. This isn’t that. This is what you actually find when you inherit a migration in progress and start pulling on threads. The Setup Mid-flight GWS to M365 migration. Test batches already running. Domain setup incomplete. Multiple migration endpoints in Exchange Online pointing at a GCP service account that nobody can confirm ownership of. This is a fairly normal state for an org-scale migration that started before all the architecture decisions were locked in. ...

The Challenge of License Management at Scale Managing Microsoft 365 licenses individually becomes unwieldy as organizations grow. Each time an employee joins, changes roles, or leaves, IT must manually update licenses. Group-based licensing solves this by automatically assigning licenses based on group membership. Prerequisites Azure AD Premium P1 or P2 license Global Administrator or License Administrator role PowerShell modules: AzureAD or Microsoft.Graph Step 1: Audit Current License Assignments First, identify all licenses currently assigned individually: ...