Migrate Outlook to Office 365: For Web, New, Classic & Mac
Published: August 10th, 2026 • 14 Min Read
For users who have recently moved to Microsoft 365, formerly called Office 365 environment – there is often a need to migrate their local Outlook data from desktop application to Office 365 mailbox or transfer Outlook.com emails to Office 365 account for centralized access over cloud.
Note: “Outlook” can refer to different products offered by Microsoft. The process to migrate Outlook to Office 365 along with emails, contacts & calendars based on the sources, number of mailboxes and rules & access.
Migrate Outlook to Office 365: Source, Destination & Data
The guide involves moving a live Outlook.com mailbox or active Outlook profile to Office 365. Read here, in case you want to:
- Import Outlook PST Files to Office 365
- Import Outlook OST Files to Office 365
- Migrate Exchange Server to Microsoft 365
Note: No migration needs to be carried out in case you have recently purchased Office 365 personal or family subscription as the mailbox remains to be the same.
Tip: To help you with your Outlook/Outlook.com mailbox migration to Office 365 accounts. BitRecover support team & migration services helps you plan, carry out and set up the post migration environment. Get in touch today.
Important Note When Migrating Outlook Web to Microsoft 365
Outlook on the Web is primarily a webmail. The actual migration depends on the connected Exchange mailbox, if it is Office 365 to Office 365 migration or Outlook.com to Office 365 migration.
Migrate Outlook.com to Office 365: With Emails, Contacts & Calendar
A direct & secure way (supports Microsoft OAuth) to move live Outlook.com emails, contacts & calendar to an Office 365 mailbox without any configuration or file export is BitRecover Outlook.com Backup software for Mac & Windows. Free trial up to 25 emails per folder.
- Download the above Outlook.com to Office 365 migration tool.
- Enter your Outlook.com email ID and Login with Microsoft.
- Select the Outlook mailbox folder you need to transfer.
- Choose Office 365 from the saving option drop down.
- Enter your Office 365 account ID & connect with Microsoft.
- Click on the Backup button.
Added Benefits of Using the Tool:
- Does not require Office 365 admin access or generating an app-password for 2FA.
- Selectively transfer only required emails from Outlook.com to Office 365 based on Date Range, Sender & Receivers Address and Subject, to ensure your Office 365 mailbox is organized.
- Supports @hotmail.com, @live.com, @msn.com & @outlook.com migration to Microsoft 365 account while preserving complete folder hierarchy & attachments.
Migrate Multiple Outlook Accounts to Office 365 as an Admin: Native Way
The IMAP Migration feature of Exchange Admin Center can be a suitable automated way in case you want to migrate several Outlook.com accounts into one Microsoft 365 tenant at once.
Note: Since the migration is carried out via IMAP – the method is only suitable to move Outlook.com emails to Office 365.
Mandatory Prerequisite: Turn on Two-Step verification and get an App Password to carry out live Outlook to Office 365 migration via EAC.
- Login to your Microsoft Office 365 administrator account.
- Choose the Admin option to access the Microsoft 365 admin center.
- Select Setup >> Migration option from the admin center.
- Choose the Email option under Migrations.
- Click the Get Started button to continue.
- Thereafter, the Email Sources tab will be open, choose Import my email messages.
- Select your data service from the available choices and choose Outlook.
- Enter your IMAP Server Name, Port Number, Security, Email Address, and Password, and hit the Save button.
- Select your Outlook.com account, enter credentials, and click the Start Migration.
- Wait for the task to be completed and choose Close Connection once the process is finished.
Practical Limitation of EAC to Move from Outlook to Office 365
The manual method to migrate Outlook.com to Office 365 is time-consuming and requires more effort than automated processes. It can also be prone to human error, as mistakes can be made more easily than with automated methods.
- It requires technical knowledge and expertise to set up 2FA.
- You can migrate only emails, not contacts and calendars.
- The maximum size limit of an email should be equal to and less than 35 MB.
- You can migrate a maximum of 500,000 emails from Outlook.com to O365.
Workaround solution to migrate Outlook to Office account without Admin access including Contacts & Calendar in one go involves: configuring your Outlook.com in Outlook Classic & then migrating Outlook to Office 365 account via the steps listed below.
Migrate Outlook Desktop Classic/New/Mac to Microsoft 365 Account
Steps as well as data transferred when migrating Outlook to Office 365 account varies based on which version of Outlook you are using. Here is quick distinction between New Outlook Vs Old Outlook:
| Outlook Classic 2016/2019/2025 to Office 365 | New Outlook Emails to Office 365 |
|---|---|
| Creates a local profile storing emails, contacts & calendar | No profile created, emails & contacts & calendar are synced Cloud |
| Bulk migration via Outlook Profile Data (via PST) >> Import into Microsoft 365 Mailbox direct via Import/Export Tool manually | Only migrate Outlook emails to Office 365 account as bulk importing the whole PST into the Microsoft 365 mailbox is not currently supported |
Learn to Create Outlook PST for Easier Migration to Office 365:
| Outlook Classic (Required only For manually migration ) | Outlook New (Requires for bulk migration with emails, contacts & calendar using BitRecover) |
|---|---|
|
Ensure you have your Office 365 account configured in Outlook.
|
Easiest Way to Migrate Outlook to Office 365 Account: New & Classic
BitRecover Outlook PST Converter is an efficient way to bulk migrate Outlook to Office 365 with complete data – Emails (with Folder Hierarchy), Contacts & Calendars irrespective of the Outlook version you are using.
- Download and launch the tool on your computer with configured Outlook.
- Choose:
- Convert Configured Outlook Mailbox: For New Outlook
- Let me Select Outlook Mailbox >> Select Folder >> Choose the exported PST: For New Outlook.
- Select the Outlook mailboxes you want to migrate to Office 365.
- Select “Office 365” from the saving drop down.
- Enter your Office 365 mailbox ID >> connect with Microsoft.
- Press “Convert” to begin the Outlook to Microsoft 365 migration process.
Extended Benefits of BitRecover to Migrate Outlook to Office 365
- Explicitly chooses to only migrate Outlook contacts to Office 365 or only Import Outlook Calendar to Office 365.
- For Outlook Classic, data is pulled directly from a configured Outlook profile, skipping manual export.
- “I am Admin” Mode enables Office 365 tenant admins to migrate multiple Outlook mailboxes to Office 365 user accounts at once without signing in to each account separately.
Manually Migrate Classic Outlook to Microsoft 365 Via PST Support
- Open Outlook Classic on your computer.
- Click on File >> Add Account & connect your Office 365 account in Outlook.
- Create PST. (Required for faster, bulk migration without much efforts)
- Click on File >> Open & Export >> Import/Export.
- Select “Import from Another Program or File”.
- Choose Outlook Data File (.pst).
- Select your Office 365 account from the drop-down under the “Import items into the same folder in”.
- Press Finish to complete.
Manually Migrate New Outlook to Microsoft 365
You do not need to create a PST in order to migrate Outlook New to Office 365 as it does not support a “bulk PST import directly into an account”. The ultimate approach to transfer Outlook emails to Office 365 is to use “manual drag & drop” by configuring an account and separately import Outlook Contacts to Office 365.
Using the manual approach to migrate New Outlook to Office 365 is not the most suitable approach for larger mailboxes – it has no filtering or bulk-select option. It is much preferred to use the BitRecover Outlook to Office 365 migration tool in such a situation.
Crucial Limitation: With the Outlook New and for Outlook.com accounts accessed via Outlook although you can not directly export only your calendar to an ICS, CSV or Excel file. Hence with the manual way will lead to data loss.
How to Migrate Outlook for Mac (Legacy & New) to Microsoft 365 Account?
Microsoft Outlook for Mac works distinctly as compared to Outlook for Windows. In Outlook for Mac (Legacy) data is stored in profile in OST format while can be exported & imported via OLM format. However, New Outlook for Mac does not create any OLM file for quicker bulk migration.
| Migration Scenario | Migrate Legacy Outlook for Mac to Office 365 | Migrate New Outlook for Mac to Office 365 |
| Manual Method |
1. Configure your new Office 365 in Outlook for Mac. (Tools >> Accounts >> Add an Account)
2. Drag/copy emails or folders from On My Mac folders/Other accounts to the Microsoft 365 mailbox to carry out Outlook for Mac to Office 365 migration.
Migration of Outlook Contacts & Calendar for Mac to a Microsoft 365 account cannot be carried out manually.
|
|
| Automated Solution |
1. Export OLM files from Outlook for Mac (Legacy). Go to Tools >> Export.
Using this approach you can migrate complete Outlook for Mac data with emails, contacts & calendar to Office 365 account at once without any issue.
|
Under New Outlook for Mac data cannot be exported to OLM files as it is directly synced from the server. For bulk migration of multiple emails accounts configured in New Outlook for Mac to Office 365 account use – BitRecover Email Backup Tool. |
Steps to Manually Import Outlook Contacts to Office 365
For users managing their Contact list on Outlook New, Classic, or Outlook Web it becomes crucial to move Outlook Contacts to Office 365 in order to not lose saved names, email addresses, phone numbers, and other essential contact details when switching accounts.
Here are the steps for the users who need to only transfer contacts from Outlook to Microsoft 365 account. The process involves exporting Contacts from Outlook to CSV and then importing Outlook Contacts to Office 365 accounts.
Step 1: Export Outlook Contacts in CSV
For Outlook New & Outlook on the Web Users
- Open Outlook on your desktop or sign in to OWA.
- Go to Contacts from the left panel.
- Click on Export Contacts >> Export.
For Outlook Classic Users
- Click on the File option, open & Export option and select Import/Export.
- Select Export to a file option and click next.
- On the next screen, select Comma Separated Values.
- Select Outlook Contacts and choose the destination path.
- Click the Finish button
Step 2: Import Outlook Contacts to Office 365
- Sign in to your Office 365 account via Outlook on the Web. (Profile icon on the right >> Sign in with a different account)
- Go to Contacts >> Import Contacts & select CSV from computer.
Steps to Manually Migrate Outlook Calendar to Office 365
You need to complete 2 phases to import Outlook calendar to Office 365 account. However, after completing the two below-mentioned stages, you can finish this task free of charge. This is recommended for small-size calendars to Microsoft 365 accounts.
Phase 1: Export Outlook Calendar in ICS Format
- Open your MS Outlook application on your Windows machine.
- Thereafter, choose the Calendar option from MS Outlook as shown in the figure.
- Select File >> Save Calendar option to continue.
- Next, choose a preferable destination and click the Save button.
Note: Now, you have your Outlook Calendar files on your machine with the file extension ICS. Let’s proceed further to import calendar to Outlook 365 mailbox account.
Phase 2: Import Calendar to Outlook 365
- Log in to your Microsoft 365 account by entering the credentials.
- Click on the Calendar option from the interface of the Microsoft 365.
- Select the Discover Calendar option to import calendar to Office 365.
- From the appeared Window, click on the From File option.
- After that, press the Browse button to select the ICS file.
- Click on the Import button to start importing ICS in Office 365.
- Once the process is completed, you will get a notification.
What Are Manual Method Limitations?
The above–mentioned process is quite lengthy and time–consuming. It requires completing two different phases to migrate Outlook calendar to Office 365. Even MS Outlook should be installed on your machine. Hence, if you have an orphan Outlook PST (Personal Storage Table) file then you cannot complete this task.
After exporting Outlook calendar data in ICS format, you can import ICS files to Office 365 one by one. Hence, it seems suitable only for importing a few ICS files. So, if there are several files then it will take a lot of time to import them into the cloud mailbox.
After you complete the transfer of emails, contacts & calendar from Outlook.com/Outlook to your Microsoft 365 user accounts you can access the data via OWA, Outlook Desktop, on mobile or any other email client.
Key Point: This migration will move your mailbox data – it does not change the identity/address of the Microsoft 365 account automatically – you are either required to set up an alias or inform your contacts about the migration.
When Should You Export Outlook Mailbox to Office 365 Account?
Here are the common user cases when one considers Outlook Web, Classic, New or Mac migration to Office 365 account:
- Moving to a business account (you\@company.com) instead of a personal account ([email protected]).
- When switching your organization from another email provider accessed via Outlook to Microsoft 365 mail server.
- In order to merge multiple Outlook.com accounts into one Microsoft 365 account.
- When restoring local data stored in Outlook Classic profile to Office 365 account to create a unified mailbox.
FAQs: Migrate Outlook to Office 365
Q: Do I need admin access to migrate Outlook to Microsoft 365?
It’s not always mandatory to have admin access to Office 365 destination accounts. However in case you are using EAC or want to bulk migrate multiple Outlook New/Classic or Live accounts to Office 365 – admin access is crucial.
Q: What happens to Outlook rules and signatures during migration?
Signature and rules cannot be migrated from Outlook to Office 365 account as they are client-side settings, not mailbox data.
Q: Will I lose data if I migrate Outlook to Microsoft 365?
No, using the appropriate method your data will be fully migrated from Outlook to Office 365 mailbox without any loss.
