Coexistence

Coexistence mode ensures mail flow and calendar visibility work across both tenants during the migration window.

Mail forwarding

TenantLift configures SMTP forwarding so that mail sent to migrated users' old addresses is automatically forwarded to their new mailboxes. This ensures zero mail loss during the transition period.

Calendar stubs

Calendar stubs keep meeting visibility intact. When a user's calendar is migrated, stubs are left in the source tenant so colleagues can still see meeting times.

Enabling coexistence

Navigate to your project → Coexistence and click Enable. TenantLift will configure forwarding rules and calendar stubs for all mapped users.

Duration

Keep coexistence active for as long as you need — typically 2–4 weeks after the initial cutover. Disable it from the same page when you're ready.