Plan & Prepare

Mail Routing for Office 365 Tenant Migration

Achieve zero mail delivery disruption during tenant-to-tenant migrations with Cloudiway's mail routing platform.

Overview

When migrating a domain between Office 365 tenants, organizations typically face a significant challenge: mail delivery disruption during the domain transfer. Cloudiway's mail routing platform provides an alternative solution that ensures continuous mail flow throughout the migration process.

Mail Routing Architecture

Incoming Email

bob@yourdomain.com

Cloudiway

Mail Router

Target Tenant

bob@tenant2.onmicrosoft.com

The Challenge

Moving a domain between Office 365 tenants typically causes two days of mail delivery disruption. During this period:

Traditional Migration Impact

  • Emails sent to the domain may bounce or be delayed
  • Business-critical communications may be lost
  • DNS propagation adds uncertainty to the timeline
  • Users experience frustration and productivity loss

How It Works

Cloudiway's mail routing platform automatically routes emails from source domains to target destinations, ensuring continuous mail flow throughout the migration.

Key Features

  • Transparent Routing

    Mail headers are not modified in any way - recipients see emails exactly as sent

  • Automatic Delivery

    Emails to bob@yourdomain.com automatically deliver to bob@tenant2.onmicrosoft.com

  • Zero Downtime

    No mail delivery disruption during the entire migration process

  • Simple Cutover

    Once complete, update MX records to point directly to target tenant

Requirements

Advance Planning Required

This service requires coordination with Cloudiway's Consulting Services team. Contact your sales manager to arrange setup.

Activation Requirements

  • Minimum 5 Business Days Notice

    Contact the Consulting Services team at least 5 business days before cutover

  • Initial Setup Call

    A discovery call to understand your requirements and configure the service

  • Testing Before Cutover

    Complete testing of the routing configuration before going live

  • Additional Service Cost

    This is a premium service not included in standard migration licenses

Migration Process

1

Configure Inbound Settings

Set up inbound mail routing rules in the Cloudiway Mail Routing tool, mapping source domains to target destinations.

2

Update MX Records

Point your MX records to Cloudiway's mail routing platform to start routing emails.

3

Complete Domain Migration

Perform the domain transfer between tenants while Cloudiway ensures continuous mail delivery.

4

Final MX Update

Once migration is complete, update MX records to point directly to the target Office 365 tenant.

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