Picture this: your company is moving from Google Workspace to Microsoft 365, and your boss is breathing down your neck about the migration. Clients missing emails, staff unable to send – a nightmare scenario.

But here's what we've learned: you can absolutely switch email providers without disruption. You just need to plan carefully, understand your DNS, and manage the transition window smartly. Here's exactly how we do it, with every step packed with what actually works.

The Scenario: Your Weekend Migration Challenge

Your company is moving from Google Workspace to Microsoft 365. You have a weekend window, but execs are anxious about any missed messages. Your mission: ensure continuity while updating DNS and completing mailbox migrations.

Here's what actually works.

Step 1: Lower the TTL in Advance (48-72 Hours Before)

Before making any DNS changes, you need agility. This is where most IT teams mess up:

• Login to your DNS provider (Cloudflare, GoDaddy, whoever you use)
• Locate your existing MX records
• Lower the TTL (Time to Live) to 300 seconds (5 minutes)

Why does this matter? This ensures DNS propagation across the globe happens within minutes, not hours, during the actual cutover. Skip this step, and you're looking at potential hours of email chaos.

Step 2: Set Up Dual Delivery or Forwarding (Your Safety Net)

If your source system (Google Workspace, for example) supports it:

• Set up dual delivery: all incoming emails are delivered to both Google Workspace and Microsoft 365 mailboxes
• Alternatively, configure a catch-all forwarding rule to redirect emails to the new host

This creates your safety net. Even if DNS propagation is delayed in some parts of the world, emails still land where they need to. Trust me – you'll sleep better knowing this is in place.

Step 3: Migrate Mailboxes (Start This Early)

Use tools like:

• Microsoft Migration tool
• Google Workspace Migration Tool (GWMME)
• IMAP sync tools (imapsync or BitTitan work well)

Migrate the bulk of mail data before the cutover. Large inboxes can take hours – so doing this early reduces pressure when you're actually switching over.

Make sure you:

• Test at least one full mailbox end-to-end
• Flag incomplete or problematic mailboxes for special attention

Step 4: Final MX Cutover (Time This Right)

On cutover day (ideally late Friday or early Saturday when nobody's watching):

• Update your DNS MX records to point to the new provider
• Ensure SPF, DKIM, and DMARC records reflect the new sending host
• Monitor DNS propagation using tools like MXToolbox

Thanks to your low TTL, propagation should be nearly instant. But expect up to 1 hour for total global consistency – patience here saves panic later.

Step 5: Post-Migration Verification (Don't Skip These Checks)

Once cutover is live:

• Send test emails from internal and external addresses
• Verify all mailboxes can send and receive without issue
• Monitor queues and bounce logs for errors
• Ask key users to check their mail clients and flag missing emails

You can optionally deactivate dual delivery or forwarding once everything is stable.

Don't Forget Security + Mobile Devices

• Review mobile device policies (iOS, Android profile changes may be needed)
• Recheck any apps or services sending emails (CRMs, contact forms, the works)
• Ensure OAuth tokens or app passwords are updated if integrations rely on your old provider

Lessons from the Field

Many IT teams fail by rushing DNS changes before lowering TTL or skipping mail migration prep. The secret is time-shifting the risk: handle heavy lifting early, and make DNS the smallest possible change at go-live.

By maintaining dual delivery or proper catch-all forwards, you prevent any disruption – even if some devices or services lag behind.

Zero Downtime is Achievable – When You Control the Timeline

Changing your email hosting doesn't need to be the disaster everyone fears. With a plan like this, you orchestrate the switch rather than firefighting it.

Downtime is a choice – not a necessity. With preparation, timing, and the right safety nets, you can deliver a seamless email migration that makes you look like the hero.