How to Migrate Gmail to Microsoft 365 in 2026: Step-by-Step Guide

What Data Can You Migrate From Gmail to Office 365?

Gmail / Google Data	Can it be migrated?	Destination
Emails	Yes	Exchange Online
Attachments	Yes / API limits	Outlook
Gmail labels	With mapping / limitations	Outlook folders / categories
Contacts	Yes, it depends on the method	Outlook People
Calendars	Yes, it depends on the method	Outlook Calendar
Google Drive	Separate Migration	OneDrive / SharePoint
Google Tasks	Method-dependent	Microsoft equivalent

Manual Methods to Migrate Gmail To Microsoft 365

There are two Microsoft Tools which can migrate, but they are not the same. Microsoft Native IMAP Migration is suitable only for email migration. Whereas the Google Workspace Migration transfers emails, contacts, & calendars.

Limitations of These Methods

Both IMAP Migration and Microsoft’s Google Workspace Migration method can be useful, but they have some limitations that companies should consider:

• IMAP mainly handles email, while other Google Workspace migration options support additional data types with their own requirements.
• Large mailboxes, high item counts, message sizes, & service throttling can affect migration speed.
• Administrators may need to configure Google Workspace, Microsoft 365, APIs, permissions, & user mappings before migration.
• Certain Google Workspace services or data types may not be included in the selected migration method.
• Native methods may provide fewer options for advanced filtering, folder mapping, duplicate handling, or selective migration.
• Administrators still need to verify the migrated data, resolve failed items, and complete the final mail-flow cutover.
• Moving many users at once can take considerable time and may require migration batches and incremental synchronization.

How Cigati Helps to Migrate Personal Gmail to Office 365

The Google Workspace Backup Tool helps users back up & migrate data from Google Workspace. It can handle Gmail, contacts, calendars, & Google Drive data, which makes it useful for enterprise users. If you want to export your Gmail to Outlook, you can also go through our detailed guide on export Gmail Emails to Outlook easily.

Key Capabilities for Gmail to Office 365 Migration

Bulk Migration via CSV	Selective Migration	Duplicate Handling	Multithreading for Faster Processing
Secure Authentication	Folder & Metadata Preservation	Resume Migration & Migration Reports	Google Drive Migration

Look at the steps for how the Cigati Gmail to Office 365 Migration Tool moves data from Gmail to O365.

Which Migration Method Should You Choose?

1. Only need email >> use IMAP method may be sufficient
2. Need email + contacts + calendars >> Google Workspace Migration
3. Large-scale migration + Google Drive >> Cigati Gmail to Office 365 Migration Tool

Pre-Migration Checklist

• List all users, mailbox sizes, shared accounts, contacts, & calendars that need to be moved.
• Identify important labels and understand how they will be represented in Microsoft 365.
• Find large messages and attachments that may affect migration time or require special handling.
• Create the required accounts and assign the appropriate licenses.
• Add & verify the organization’s domain in Microsoft 365 before the final cutover.
• Make sure destination mailboxes are active and ready to receive migrated data.
• Confirm administrator access, authentication, API settings, and required migration permissions.
• Migrate a small group of users first to identify configuration or data-mapping issues.

How to Handle Gmail Labels During Migration?

Gmail labels work differently from Outlook folders, so the mailbox structure may change after the migration process. After that, a single Gmail email can have several labels, while Outlook generally organizes messages into folders.

Before migration, review the label structure and identify important labels and nested labels. Map them to suitable Outlook folders where possible. Also check Gmail system folders because they can sometimes result in duplicate messages during IMAP migration.

After migration, users should understand that their Gmail labels may not look exactly the same in Outlook. Also, a quick review of the migrated folders & sample emails can help confirm that the important messages are in the expected locations.

Common Problems Occur When Migrate Gmail to O365

A migration problem may arise even after the correct initial setup. Missing emails, incorrect folder mapping, authentication failures, & slow migration are some of the issues administrators may encounter.

Problem	Possible Cause	Solution
Gmail emails are missing after migration	This migration may not have included all Gmail folders or labels. With an IMAP-based migration, only supported mail folders are transferred. Gmail’s label structure can also affect how messages are exposed through IMAP. Microsoft notes that IMAP migration does not transfer contacts, calendars, or tasks.	First, you have to compare the source & destination mailboxes. Check the Gmail labels and folders that were included in the migration. Review the migration report for skipped or failed items & check whether the affected messages are present under another folder in Microsoft 365. If the migration method has data-type or folder limitations, use a method that supports the required Gmail data.
Contacts are missing	Email migration and contacts migration are not necessarily handled by the same process. Microsoft specifically lists contacts as data that is not transferred through an IMAP migration.	Confirm whether the migration method supports contacts. If it does not, export or migrate the contacts separately through a supported method. After importing them into Microsoft 365, verify names, phone numbers, & other important contact fields.
Some Attachments were not migrated	The affected message may exceed the migration method’s supported message size, or the item may have failed during synchronization. Microsoft documents a 35 MB maximum message size for its IMAP migration process.	Check the migration report for failed or skipped messages. Identify whether the missing attachments belong to messages that exceed the supported size or contain an unsupported item. For important mailboxes, compare a sample of large messages between Gmail & Microsoft 365 before completing the migration.

Best Practices for Gmail to Microsoft 365 Migration

• Make sure to audit before migration
• Map users before copying data
• Migrate in controlled batches
• Keep the source environment available temporarily
• Communicate label/folder changes to users
• Always monitor migration reports

Gmail to Microsoft 365 Migration: Native Tool vs. Migration Software

Factor	Native Microsoft Tools	Migration Software
Email Migration	✔️	✔️
Calendar/Contact Migration	Method-dependent	✔️
Bulk Processing	✔️	✔️
User Mapping	Manual configuration	✔️
Filters	Limited	Advanced
Incremental Migration	Available depending on method	Usually Available
Detailed Report	Limited	Complete Report-Folder-Wise
Google Drive Migration	Separate Process	Tool-dependent

After Migration, Change DNS

Remember this: you must change your DNS after the completion of migration. Make sure you update your DNS and MX records. If you face any difficulties then contact our support team.

Conclusion

When you migrate Gmail to Microsoft 365, it requires more than moving emails from one mailbox to another. The right migration method depends on the type and amount of data you need to transfer. However, IMAP can work for email-only migrations, while Google Workspace migration methods can support additional data such as contacts and calendars.

Before you start, audit the source accounts, prepare Microsoft 365, & test the migration with a small group. For larger migrations that also involve Google Drive & mapping, or detailed reports, a Cigati Google Workspace Backup Tool can provide additional migration options.

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