Import MBOX to Exchange and Exchange Online
If you are an IT admin who is in urgent need of depositing tens of thousands of MBOX files into user accounts inside a local Exchange Server or its cloud counterpart, then you are in luck. Here we have for you the most advanced solutions to import MBOX to Exchange Server or Exchange Online (the M365 cloud variant of the on-premises setup).
Table of Contents
No matter what the origin of your MBOX files is, be it Thunderbird profiles, Apple Mail, or anywhere else, we have a universal solution that works regardless.
So let us begin our discussion by highlighting what happens if you continue to keep your MBOX files orphaned and why it is a good idea to put them on a server, be it local or cloud.
Why Should Admins Migrate their MBOX to Exchange Server/Online?
Some common reasons for reattaching .mbox files to user accounts are as follows:
Centralization: A successful import consolidates all the scattered MBOX files into one single place. Making management easy.
Unlocks Advanced Features: MBOX files in and of themselves are of little use; they just sit there like any other text file. However, once inside an email processing unit, individual messages can be forwarded to recipients. Communication can take place effectively. Plus, errors like your mailbox has been temporarily moved to the Microsoft Exchange Server will resolve on their own.
Safety: Raw MBOX data can’t be encrypted. Not natively, that is, admins have to use external tools and techniques to keep their data safe. On the other hand, once you import MBOX to Exchange Online or even the local server, you dont need to do anything; the server takes over the security responsibility.
These are just some of the many advantages of putting MBOX in Exchange. So now that we are aware of these opportunities, let us see how to grab them.
Pre-plan your MBOX to Exchange Import
Before you take even a single email to the cloud or the local server, you need to ensure that they fulfill certain quality checks. This is a key step of any successful transfer, so do the following:
Make an inventory of all MBOX files. This means to locate and arrange the MBOX data in a predefined space from where the transfer will take place.
Clean up any corrupt MBOX files or fix them. Make sure your Exchange Online environment is ready to receive the files, i.e., it has all the user accounts with appropriate licenses and enough storage space.
Communicate with all stakeholders to ensure that everybody is informed about the changes and prepared for any downtime.
The planning phase also involves running a pilot import, preferably with synthetic data, to test if all the connections that you made are solid and data is being deposited in the correct accounts or not. Patch any errors and move on to the main import task.
Import MBOX to Exchange Server Manually
This is done with the help of the free-to-use Thunderbird email client. For your convenience, we have split the steps into two stages.
Stage 1. Adding an On-Premise Exchange Server Account to Thunderbird
Before you begin, go to Thunderbird settings and “allow cookies from sites”. This is not required but recommended.
Then, File > New > Email Account.
Enter name, email ID, and password.
Thunderbird automatically configures the Incoming Server data, but verification is a must:
- Protocol: IMAP
- Server hostname: Your Exchange Server’s FQDN (e.g., mail.yourdomain.com or your_internal_server_name.local)
- Port: 993
- Connection security: SSL/TLS
- Authentication method: Normal password
- Username: Your complete email address (or your Windows username if required by your admin)
Repeat the same for the Outgoing Server as well, so that you can import MBOX to Exchange without any issues:
- Server hostname: Your Exchange Server’s FQDN (e.g., mail.yourdomain.com or your_internal_server_name.local)
- Port: 587
- Connection security: STARTTLS
- Authentication method: Normal password
- Username: Your complete email address (or your Windows username if required by your admin)
You will be prompted by Thunderbird to enter your password directly. No need to export the Exchange mailbox to Thunderbird.
Stage 2. Importing MBOX Files to Thunderbird
Step 1. Open Settings > Add-ons and Themes > Toggle Extensions tab and type ”ImportExportTools NG” in the search bar.
Step 2. Click on Add to Thunderbird, then Add. Thunderbird will add the extension.
Step 3. Return to Thunderbird main screen, right-click on “your account” and create a new folder specifically for your imported emails.
Step 4. Right-click on the folder you made, take the mouse over “ImportExportTools NG,” and choose to import MBOX files to Exchange.
Step 5. Browse for MBOX files, select, and import.
Terror of Errors During a Manual MBOX to Exchange Import
Admins may face issues at any time during the manual import that too, without any warning. Plus, there are scenarios that the manual method may not be able to handle like for example:
The problem is with the vast variety of MBOX files. Users who have worked with MBOX files in the past may know that there is not one, not two, but 4 different kinds of MBOX files. Some of them have the plain old .mbox extension, some come with a .mbx, and there may be a few extensions with fewer MBOX files as well. If an admin is manually adding them, there is a high possibility that some get left out, as the person uploading the content may not know how to filter the data correctly.
And this is the case for just one user. What happens when there are thousands of users( which is often the case in modern workplaces), each with many different MBOX files? I will tell you what happens: The import MBOX to Exchange task becomes so hectic and time-consuming that it ends up being a negative ROI. No admin or organization wants that to happen.
Moreover, the most commonly suggested remedy in forums and other places is using the Thunderbird client. The idea is you set up your account in Thunderbird, add an extension called ImportExport NG, and use it to directly deposit the MBOX into the destination account. This is not a bad approach for personal users; we have included that approach in our guide. The real problem begins when the admin has to coordinate this across the entire organization.
It doesn’t take long for a simple file uploading task to become an endless spiral of one troubleshooting incident after another. So it is recommended that you go with the professional approach.
Conversion-Free Direct Import of MBOX Files to Exchange Online
As we know, Exchange Online is the email management part of the Microsoft 365 admin suite. So to put our MBOX files in M365, we just have to use the best-known tool out there. Which is none other than the SysTools MBOX to Microsoft 365 Importer.
This tool supports both Exchange Online Plan 1 and Plan 2, plus it can be used with any Microsoft 365 business/enterprise-level plans as well.
The tool is entirely GUI with no scripting requirement whatsoever, making the entire export super easy for even novice admins handling their first-ever mass import. If your MBOX is from a source that allows folder structure(like Google Takeout). Then, this tool can replicate the entire folder structure down to the last nested item.
Moreover, even if your MBOX files are to be put into a shared mailbox that doesn’t have the same login/ license requirements as a regular account, don’t worry. The tool can easily handle this scenario as well. Also, it goes without saying that every MBOX variation, be it at the file extension level or file source level, can be imported into Exchange Online with this tool, no questions asked.
Step-by-Step Import with a Professional Tool
Here is the list of steps you need to take (Please Note: These are for Exchange Online only; for the local Exchange Server, convert raw MBOX into PST, EML, or MSG, then use the same tool but with different endpoints.)
Step 1. Launch the Tool, select MBOX as the source, and Microsoft 365(Exchange Online) as the destination.
Step 2. Then, scroll down a bit and select email workload. You will also see a date filter; apply it to make your import MBOX to Exchange task more precise.
Step 3. Go to the source screen, make sure your MBOX files are in the correct format, which is as follows: The main MBOX containing user name folders containing the MBOX files. Fill in the folder path, validate, and Next.
Step 4. On the source screen, fill in the required admin credentials, validate, and hit Next.
Step 5. Map the users with any one of the available options.
Step 6. Preview the user list, select, prioritize, add destination account, validate, and import.
Conclusion
In this article, we have had a discussion about how a user can migrate their email data from MBOX to an Exchange server mailbox. There were two major steps that we had discussed in the above section for the migration or conversion of MBOX files. The first major step is to add an Exchange Server account to Thunderbird, then upload the MBOX data. If your intended destination is on the cloud and you want to import MBOX into Exchange Online, then there is no better way than the tool that is described here. Use it and end all your woes.
Frequently Asked Questions
Q. Are the steps to import MBOX to Exchange any different depending on what type of MBOX file I have?
No, the steps remain exactly the same for every sub-file type in the MBOX family of electronic mail messages.
Q. Is there a limit on how many MBOX files I can import into Exchange Online or Exchange Server?
Limits do exist, but they are dependent on how much storage you have available in the Exchange Online account or Exchange Server database. If you are trying to import more than what’s available, then it’s not at all possible. Otherwise, you are free to upload.
Q. Can I perform filtering during the import process?
If you choose the manual route, then no, it’s not possible. On the other hand, the tool we prescribe here contains a dedicated date filter mechanism you can use to decide from which time period the MBOX files are picked before they’re deposited in the Exchange Online environment.
Q. How much time does it take to import MBOX in Exchange?
Giving an accurate timing of operation completion is difficult as it depends on many different factors, like the amount of data you have, your network bandwidth, and the approach you are opting for. What I can say for sure is that no matter what parameter you measure, the tool will give you superior performance than any manual method, so use it if you want quick results that are also on time.