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Read time 6 minutes

Summary: This blog discusses the process of migrating user emails from IMAP-enabled email servers to Office 365 using the Office 365 Admin Center. It highlights some limitations, such as the inability to migrate contacts, calendars, and tasks, and sets maximum limits for items and email size. The article provides step-by-step instructions for both listed and non-listed email providers, emphasizing the complexity of the manual process. It suggests using Kernel IMAP to Office 365, a third-party tool, for a more efficient and user-friendly migration experience.

Effortlessly transition user emails from their IMAP-enabled email servers to Office 365 through the use of the Internet Message Access Protocol (IMAP). However, it’s crucial to familiarize yourself with certain limitations before embarking on the migration process.

  • Only the inbox items or other email folders can be migrated. You cannot migrate contacts, calendars, and tasks.
  • A maximum of 500,00 items can be migrated from a user’s mailbox
  • Maximum size limit for an email is 35MB

To migrate user’s mailboxes with IMAP in Office 365 admin, go to Setup and select Data Migration to start migrating IMAP-enabled emails. The email migration page in Office 365 admin center is pre-configured to migrate emails from Gmail, Outlook, Hotmail, and Yahoo.

Note: Before starting the migration, make sure that you have added the users to your Office 365 account. To know about adding users to Office 365 account, visit Add users to Office 365 for business

Instant Solution

Download automated tool Kernel IMAP to Office 365 to migrate IMAP email servers data to Office 365 without any data loss or interruption.

IMAP to Office 365 Migration using Office 365 Admin Center

Now, let us see how to migrate IMAP mailboxes from Office 365 admin center. Follow the below steps:

  1. Go to Office365.com and sign in with Admin credentials.
  2. Now, navigate to Setup in the menu and select Data Migration.
    select Data Migration
  3. On clicking Data Migration, the “Select your data service” dashboard will appear on the screen. If your email provider is listed in it, then select it.
    Select your data service
  4. After selecting the email provider, you will be redirected to select users.
    Select the email provider

  5. Select the users that you want to migrate and fill the email alias & password.
  6. Click “Start Migration” at the left corner of the wizard after entering the required information.
    Click Start IMAP to Office 365 Migration
  7. The migration process progresses through several status stages, including: “Starting,” “Queued,” “Syncing,” and finally “Synced.” When the status reaches “Synced,” simply click the “Stop Migration” button to conclude the process seamlessly. After completion, click “Close Connection” to finalize the task.
  8. Using the same technique, you can also migrate from other IMAP email servers.

How to Migrate from IMAP to Office 365 if Your Provider is Not Listed?

Transitioning from IMAP to Office 365 is a straightforward endeavor when dealing with listed email providers. However, should your email provider not appear on the list, the process may become more intricate. In such cases, please follow the steps outlined below for non-listed email providers.

  1. Select other email sources from “Select your data service” dashboard.
  2. Now, fill the IMAP connection data with appropriate details to test the connection. You can use any IMAP account for this. Look at the below example for Google apps. Click the “Save” button to test the connection.
    Fill IMAP connection data
  3. Once the connection is established, it will display all the user mailboxes for the provided email address.
  4. When transitioning from email providers not listed, you’ll need to furnish an application password. Once you’ve supplied these credentials, proceed to follow the aforementioned steps, specifically steps 5 through 7, to successfully migrate the user’s email data.

However, if you’re migrating from Google apps with your own domain, then you need to create DNS records at Google Domains for Office 365 once the migration is complete. This is necessary to send the emails to Office 365 mailboxes rather than Google apps. If you migrate from other IMAP email providers where you own the domain, then check specified instructions to find the domain provider.

Migrate IMAP to Office 365 without Complexities – Kernel IMAP to Office 365

As you can see, migrating IMAP mailboxes to Office 365 with Admin Center is not an easy option. Also, this process is not viable for non-technical users. So, you should use a third-party tool that allows to migrate IMAP to Office 365 mailboxes efficiently. Kernel IMAP to Office 365 is an advanced software that is specially designed to migrate mailboxes from different IMAP servers to Office 365. It has some advanced features that make the migration process convenient and simple.

  • Allows migration of single/multiple mailboxes from IMAP email servers
  • Bulk migration of IMAP mailboxes using CSV file
  • Allow easy migration of archive mailboxes as well as public folders
  • Smart filtering options to migrate specific mailboxes or data
  • Saves the migration report in a CSV format
  • Successfully migrates to different versions of Exchange and Office 365
  • Compatible with almost every IMAP email server like Yahoo, Gmail, G Suite, AOL, Zimbra, etc.

Using this software, anyone can migrate IMAP mailboxes to Office 365 without any data loss or interruption. This tool can also be used to migrate IMAP mailboxes to Exchange Online and On-premises.

Step-by-Step Software Video to Perform IMAP to Office 365 Migration



In this blog post, you’ve been introduced to the manual process of migrating IMAP mailboxes to Office 365. This process involves using the Exchange Admin Center and includes different procedures for listed and non-listed email providers. However, it’s worth noting that this method can be time-consuming, complex, and comes with certain limitations. These limitations include support for only email migration, a limited number of mailbox items (maximum of 50,000), and a maximum email size of 35 MB.

To address these challenges, we’d like to introduce you to an alternative solution: the Kernel IMAP to Office 365 tool. This tool streamlines the migration process by offering automation, reducing the number of steps involved, providing a user-friendly graphical interface, and incorporating several other remarkable features.