Gmail to Outlook
Migration

Two different migrations, same destination

Individual mailbox migration: You have one Gmail account and want its email, contacts, and calendar inside Outlook — either the desktop app, Outlook.com, or Outlook as part of a Microsoft 365 personal or business subscription you already have. This is typically done via IMAP or Outlook's built-in "Add Account" import flow.

Company-wide migration: Your business runs on Google Workspace and is switching the entire organisation to Microsoft 365, with Outlook replacing Gmail as the primary email client for every employee. This requires Google Workspace admin access, Microsoft 365 admin access, and a structured, batched migration — not something done mailbox-by-mailbox by hand.

What actually moves during the migration

For both approaches, the goal is the same three things:

• Email — every message, across every Gmail label, preserving folder structure as closely as the destination platform allows
• Contacts — your Google Contacts list, including any contact groups
• Calendar — events, invites, and recurring meetings from Google Calendar into Outlook Calendar

Attachments migrate with their emails. What does not automatically migrate: Gmail filters and auto-forwarding rules, which need to be manually recreated as Outlook rules since the two platforms use fundamentally different rule engines.

Gmail labels vs. Outlook folders

This is the detail that trips people up most. Gmail uses labels, which are not mutually exclusive — a single email can carry multiple labels at once (e.g. "Work" and "Urgent" on the same message). Outlook uses folders, where a message physically lives in one place. When a labelled Gmail email has more than one label, most migration tools will either place a copy of that message in each corresponding Outlook folder, or default to the first label as the "primary" folder. Neither is wrong, but it's worth knowing in advance so your mail structure doesn't look unexpectedly different on the other side.

Step-by-step: migrating a single Gmail mailbox to Outlook

1. Enable IMAP access in Gmail settings (Settings → See all settings → Forwarding and POP/IMAP → Enable IMAP).
2. Generate a Google App Password if two-factor authentication is on — Gmail will not accept your normal password for IMAP access in that case.
3. Add the Gmail account to Outlook using the app password, or use Outlook's dedicated "Import from Gmail" wizard where available.
4. Let the sync complete — for large mailboxes (tens of thousands of emails), this can take several hours; leave the client open and connected.
5. Recreate any Gmail filters manually as Outlook rules, since these don't transfer automatically.
6. Verify calendar and contacts imported correctly, particularly recurring calendar events, which are the most common casualty of manual migration.

Step-by-step: migrating an entire company from Google Workspace to Outlook / Microsoft 365

This is a fundamentally different exercise, run at the admin level rather than per-mailbox:

1. Discovery — inventory every mailbox, shared mailbox, distribution group, and calendar resource in Google Workspace.
2. Microsoft 365 tenant setup — provisioning users, licenses, and mail-enabling every account that will be migrated.
3. Domain and DNS preparation — verifying your domain in Microsoft 365 and preparing MX record changes for cutover day.
4. Batched migration — mailboxes are migrated in planned batches rather than all at once, so issues surface early on a small group rather than affecting everyone simultaneously.
5. Delta sync — a final pass that catches any email received between the initial migration and cutover, so nothing sent during the transition window is lost.
6. MX cutover — mail routing switches from Google to Microsoft 365, typically scheduled outside business hours.
7. Validation — item counts and spot-checks confirm everything arrived intact before the Google Workspace environment is decommissioned.

This is exactly the process covered in more depth on our Google Workspace to Microsoft 365 migration service page.

Common pitfalls to plan for

• Duplicate contacts — merging Google Contacts with an existing Outlook contact list can create duplicates if not deduplicated beforehand.
• Recurring calendar events breaking — the two platforms represent recurrence rules differently; complex recurring meetings (e.g. "every second Tuesday") are the most likely to need a manual check.
• Shared mailboxes and delegated calendars — these require separate handling from individual user migration and are easy to overlook in a DIY approach.
• App passwords and 2FA — IMAP-based migration breaks silently if 2FA is on and an app password wasn't generated; always confirm this before starting.

Which approach is right for you?

A single personal mailbox is reasonable to migrate yourself using IMAP or Outlook's import wizard, with an afternoon set aside for verification. A full company migration — anything beyond a handful of users, or any organisation with shared mailboxes, distribution groups, or compliance requirements — is worth handling as a structured project rather than a DIY task, given how much can go quietly wrong with filters, permissions, and calendar fidelity at scale.