Migrate iRedMail to Office 365: A to Z Guide

Organizations that currently still rely on open-source systems like iRedMail for managing their email traffic are becoming outdated. In the age of AI, where productive tools dominate, basic email services no longer fulfill all business requirements. That is why there is a hard push to migrate iRedMail to Office 365.

Don’t worry, we will help you in your transition from an on-premise system to the cloud.

What to Do Before You Migrate iRedMail to Office 365?

This is the pre-migration phase, where you make the source and destination ready to perform a migration.

Veteran IT administrations know that the secret to a successful migration lies in how good your preparation is. You need to complete these processes before you move anything out of the source.

Chart out a route and communicate with your stakeholders. Ideally, migration should happen when the network is free from the usual user activity. So schedule it for the weekend or another low-activity period(off hours). Tell the users in advance about the changes that are happening so it does not come as a surprise.

Get your M365 Tenant ready to accept the bulk load of data. You can’t just push a large amount of email data straight to the Office 365 environment and expect it to work. It is important to first make user mailboxes, and if possible, also create folders for all mailboxes in Exchange Online.

Gather iRedMail Server Details. You need the fully qualified domain name (FQDN) of your iRedMail server (e.g., mail.yourcompany.com). Also, confirm it accepts secure IMAP connections on port 993. Moreover, admins must make a second copy (consider it as a backup if you will) to safeguard against black swan events.

This was a list of generalized steps applicable across different setups. Depending on how you use iRedMail, you might have to do more.

Once all the preparation is complete, move on to the actual movement of data.

Take Your iRedMail User Data to the Microsoft 365 Cloud with Manual Migration

Office 365 Admin Center has a section dedicated specifically for migration-related requests, so if your admin account is all set up and user accounts are ready with proper licenses, use this facility.

All you have to do is log in to the main Admin center > look for the Migration section in the left pane > and click on Add new batch.

You will have to create a migration endpoint in Office 365 for the iRedMail account.

Do that and follow the rest of the instructions as they appear on your screen.

Download Email Files, Convert and Send to Microsoft for Uploading

This method sounds simple, but it is not. The first challenge is aligning the output format you get from iRedmail to the one that will be acceptable inside M365.

As the native format you get out of iRedMail is Maildir. So you need to use a Mildir converter tool to change the file format in either EML (makes it import-friendly in the New Outlook client) or the PST format (to use the classic Outlook for import).

Another option that admins with a relatively smaller user base can try is using Microsoft’s classic Outlook to set up the iRedMail and export the data.

Note that even though the New Outlook client has the export mailbox facility, it is limited to accounts ending with the @outlook.com domain. Not even premium M365 business accounts get this feature.

Also, you might not know that if your users are able to set up both iRedMail and their new m365 account in the same client, it is possible to drag and drop emails from one account to another. However, as this creates more problems than solutions, it is best that you avoid it and go forward with more tried and tested approaches.

Once you have the PST file, use the Network upload or the Drive Shipping method to make these files appear in the user’s M365 email address.

Alternatively, you can use a professional Office 365 PST import tool to speed things up.

Steps to Use the Tool to Migrate iRedMail to Office 365

Step 0. Download the SysTools IMAP to Office 365 Migration solution.

Step 1. Open it and select IMAP as the starting point and Microsoft 365 as the destination.

Step 2. Scroll down a bit and see if the checkbox next to the email workload is enabled or not. If it isn’t, enable it and apply a date filter. Then press Next.

Step 3. On the source screen, you have to conduct the server name and port validation from where the data will be pulled. Press the Validation button, and a green check mark means you are good to go. So, press Next to continue.

Step 4. Like we did in the last step, here also we have to make a validation. Enter the M365 admin credentials and Application ID in their respective fields, press Validate > then hit Next.

Step 5. On the user mapping screen, you first have to download a template and then fill it in with the user details. Save the CSV and reupload it into the tool with the Import Users button.

Step 6. The final page, where you see the list of users, along with the option to make a more refined selection, a priority mark option that tells the tool to migrate that particular user ahead of others. Here you can edit out any typos/mistakes that are in the user name. Validate and start the migration.

Complete Post Migration Checks

A single migration run is not enough to bring all the data together. As migration usually takes time, it is almost guaranteed that users will get new messages in their accounts. It is important that admins migrate these messages as well.

However, the problem is that if the administrator took the manual route to migrate iRedMail to Office 365, there is no way to filter these messages from the rest of the migrated content.

Adding yet another manual step to the already lengthy process. On the other hand, the tool we prescribe comes with a built-in Delta migration facility. It can detect all the newly arrived data and migrate only those particular emails in the second run.

Lack of reporting in the non-tool-based migration methods keeps the process opaque. So admin won’t know whether their efforts were successful or in vain until the very last moment.

The tool, on the other hand, updates in real time, showing exactly how many emails have been moved. Plus, when the migration ends, IT admins using the tool can generate a summary a well as a detailed report to do a more in-depth assessment of the migration.

iRedMail does not provide you with any email address, which means you were using some other domain provider service. So now that the emails are, we have to ensure all future emails get rerouted to the new user email addresses. For this, you have to change the MX records, update the TXT and DNS values. This step is mandatory regardless of the method you use.

When you are doing this, also change the SPF record to include Microsoft’s servers and create a CNAME record for the Autodiscover service.

Schedule training for the users to make them familiar with the new M365 environment.

Conclusion

Here we saw how to migrate iRedMail to Office 365 in three different ways. The first one involved using the manual method present inside the M365 admin center. The second method called for exporting the emails from the iRedMail server, changing them to a M365-compatible file, and adding them to the cloud. At last, we gave the steps to use an automated tool that made the migration super easy.