When introducing IMAP migration, it’s important to explain its purpose, benefits, and the process involved. With so many factors and tools to consider, pulling off a successful migration will take lots of preparation and planning. Here’s everything to know.
Benefits of Migrating From IMAP to Office 365
Migrating from an IMAP server to Microsoft 365 brings a host of benefits that can greatly improve an organization’s productivity, collaboration, and overall efficiency. While IMAP servers typically synchronize only emails, Microsoft 365 synchronizes all essential data, including emails, calendar items, contacts, tasks, and notes, creating a more integrated and seamless experience.
Storage limitations are another common issue with IMAP servers, as they often provide limited space based on the provider. In contrast, Microsoft 365 offers generous mailbox storage, with standard users receiving 50GB and up to 100GB available for those on an E5 plan (as of 2021).
What’s more, while IMAP servers don’t include productivity software, Microsoft 365 comes with a comprehensive suite of tools, including Word, Excel, PowerPoint, SharePoint, Teams, and OneDrive.
Advanced email features, such as folder creation and email flagging, may not be fully supported across all devices with IMAP. However, Microsoft 365 ensures these features are available and consistent across all devices. Security is another area where Microsoft 365 excels, offering robust protection through Advanced Threat Protection, data loss prevention, and other security measures.
Support can vary widely with IMAP providers, often requiring additional fees for premium assistance. In contrast, Microsoft 365 provides 24/7 professional support from Microsoft, ensuring users receive help whenever needed. Finally, while backing up data on IMAP servers may necessitate third-party solutions, Microsoft 365 includes built-in options for data backup and recovery, adding another layer of convenience and security for organizations.
Things to Consider for an IMAP Migration
When planning a migration to Microsoft 365, it’s important to be aware of a few limitations that could impact the process. For instance, Microsoft’s data migration tool does not account for tools that enforce messaging records management (MRM) or archival policies.
If messages have been deleted or moved to an archive due to these policies, the migration tool may flag them as “missing,” leading to the perception of data loss rather than actual loss. This can complicate content verification checks, making it harder to distinguish between perceived and real data loss. To avoid this issue, Microsoft strongly recommends disabling all MRM and archival policies before starting the migration process.
Additionally, this type of migration only allows for the transfer of items within a user’s inbox or other mail folders, meaning contacts, calendar items, and tasks will not be migrated.
There are also limitations on the volume and size of emails that can be transferred; specifically, you can migrate up to 500,000 items from a user’s mailbox, with emails being transferred from the newest to the oldest, and the maximum size for any single email is 35 MB.
To improve migration performance, especially if your source email system has connection limits, it’s advisable to increase these limits. Common limits include the total number of client/server connections, per-user connections, and IP address connections on either the server or the firewall.
The Impact an IMAP Migration Has on Users
To successfully migrate emails, you need access to the user mailboxes in your source email system. Suppose you already know the user passwords or can access their mailboxes using administrator credentials. In that case, the migration process will not impact users until the source email system is eventually shut down.
However, you will need to reset the passwords if you do not have access to the user mailboxes. This will allow you to access the mailboxes with the new passwords you’ve set.
It’s important to note that if users are unaware of these new passwords, they won’t be able to access their old mailboxes during or after the migration. If you want users to retain access to their old mailboxes, you can distribute the new passwords to them after the migration is complete.
Pre-migration Assessment and Preparation
To successfully migrate email from an IMAP server to Office 365, start by identifying the source IMAP server, whether it’s Gmail, Yahoo, or a custom IMAP server, and gather all necessary login credentials for each email account that needs to be migrated. Next, determine the amount of data in each mailbox to estimate the time required for the migration process.
It’s also crucial to review the data for any potential issues that might affect the migration, such as the size and format of attachments or the structure of folders. Preparing the Office 365 environment involves creating user accounts and assigning licenses, ensuring that the usernames match the email addresses from the IMAP server to streamline the migration.
Finally, verify that your network bandwidth can accommodate the migration, particularly if you are handling a large volume of data simultaneously.
Setting up Office 365
To set up email migration from an IMAP server to Office 365, start by creating users and assigning licenses in Office 365. Access the Microsoft 365 admin center to add users either individually or in bulk and ensure that each user is assigned the appropriate licenses. Each user’s primary email address must match the one used on the IMAP server to ensure that emails migrate correctly.
Next, configure Exchange Online by navigating to the Exchange Admin Center, which can be accessed through the “Exchange” option under “Admin Centers” in the Microsoft 365 admin center. Within the Exchange Admin Center, migration endpoints are set up, which are necessary for Exchange Online to connect with and retrieve data from the IMAP server.
Starting the IMAP Migration
To begin migrating email from an IMAP server to Exchange Online, first sign in to Microsoft 365 with your admin account. Access the Exchange Admin Center by selecting “Admin” from the app launcher or directly visiting the Microsoft 365 admin center, then navigating to
Exchange” under “Admin Centers.”
In the Exchange Admin Center, go to “Recipients” on the left and select the “Migration” tab. Click on the “+” button and choose “Migrate to Exchange Online” from the dropdown menu. Select “IMAP migration” and proceed by clicking “Next.”
On the “Select the users” page, click “Browse” to upload a CSV file listing the email addresses of the mailboxes to be migrated. The CSV file should include an EmailAddress column, and optionally, columns for Username and Password if required by the IMAP server. After uploading and verifying the CSV file, click “Next.”
Confirm that the IMAP server settings are correct and click “Next.” Name your migration batch, choose the migration endpoint you have previously set up, and select the target delivery domain where Microsoft 365 will route emails during the migration.
Finally, decide whether to start the migration batch automatically or manually at a later time.
Post-migration Tasks
To finalize the email migration to Microsoft 365, first verify that all email data, including items in the inbox and other folders, has been successfully migrated. Address any issues, such as mailbox quota exceedances or large items, using the migration dashboard in the Exchange Admin Center.
Users need to reconfigure their email clients to connect to their new Microsoft 365 mailboxes. Import any PST files that were not migrated.
Update your domain’s MX records to route new emails to Microsoft 365, allowing up to 72 hours for propagation. Once confirmed that all data has been moved and new emails are correctly directed, decommission the old IMAP mailboxes.
Finally, train users on accessing their email and calendar in Microsoft 365 using Outlook or other supported apps.
How Coherence Inc. Can Help with IMAP Migration
Coherence Inc. provides expert assistance for IMAP migration to Microsoft 365, ensuring a seamless transition. We start by meticulously planning the migration process, including assessing data volumes and identifying potential issues.
What’s more, our experts can handle the setup and configuration of migration endpoints, ensuring both the source IMAP server and Microsoft 365 environment are properly prepared for data transfer.
Call Coherence Inc. today to see how we can help with all of your migration needs.
