In the fast-moving digital world, cloud-based platforms like Office 365 (Microsoft 365) have become the first choice for both individuals and businesses. They offer better accessibility, greater security, and a more reliable ecosystem compared to traditional desktop-based email clients. Because of this shift, users often need to move older emails saved in EML format into Office 365.
EML files are commonly generated by email applications such as Thunderbird, Windows Live Mail, Apple Mail, eM Client, Zoho Mail, and many others. But Office 365 does not support EML files directly, which makes users search for the safest way to Import EML emails into Office 365.
This blog explains everything you need to know reasons for migration, challenges, manual workarounds, and the easiest automated method for both Windows and Mac.
What Are EML Files?
An EML file is a single email file that contains Subject line, Sender & receiver details, Email body, Attachments, Metadata like time, headers, etc.
Many email clients export or save emails in this format. However, Office 365 does not allow direct EML import, so conversion is necessary.
Why Import EML Emails into Office 365?
There are many reasons why users plan to upload their EML messages to Microsoft 365:
- Cloud Accessibility
Office 365 stores all emails on Microsoft’s cloud servers, enabling access from Windows, Mac, iPhone, Android, Browser. This makes email access easier than using EML files stored locally.
- Security & Compliance
Office 365 offers advanced features like MFA (multi-factor authentication), Encryption, Spam & malware protection, Data loss prevention (DLP). These features help protect emails better than local EML files.
- Centralized Mailbox Management
Users or businesses can store all email communication under one account, eliminating scattered EML files.
- Migration to Outlook
Many users switching to Outlook want all their old emails uploaded to Office 365 as well.
Challenges in EML to Office 365 Migration
While the need is common, the process is not straightforward there are some key issues like:
- Office 365 cannot import EML directly.
- Drag-and-drop works only in desktop Outlook, not in web Outlook 365.
- Converting hundreds of EML files manually is slow.
- Attachments may be lost during manual import.
- Formatting like HTML, images may break.
- Folder structure is not maintained automatically.
Because of these limitations, users need a more dependable process.
Manual Methods to Import EML Emails to Office 365
There is no direct manual method, but some workarounds exist. These work only for small conversions.
Method 1: Upload EML into Outlook to Sync Outlook with Office 365
This method to Import EML emails into Office 365 applies to both Windows and Mac.
Step 1: Import EML files into Outlook
- Open Outlook.
- Create a new folder.
- Drag and drop the EML files into that folder.
Step 2: Configure Office 365 in Outlook
- Go to File then Add Account.
- Enter your Office 365 login details.
- Outlook will sync with Office 365 automatically.
Step 3: Move emails to Office 365
Drag the imported EML emails from the local folder and drop them into your Office 365 mailbox folder.
Limitations:
Works only for small batches.
Attachments may break when dragged.
Slow syncing if mailbox is large.
Requires Outlook installed.
Method 2: Import EML Emails into Office 365 by PST
If drag-and-drop doesn’t work, users often use this indirect method.
Steps:
- Convert EML to PST using any converter tool.
- Open Outlook then File and choose Import/Export.
- Import the PST into Outlook.
- Sync the imported emails to Office 365.
Limitations:
- Multi-step process.
- Requires converting tool.
- Takes time for large files.
Method 3: Upload EML to another IMAP Account to Sync with Office 365
A longer alternative but works:
- Add a Gmail/Yahoo/IMAP account to your email app.
- Upload EML files to this IMAP account using an email client.
- Use Office 365 migration options to import the IMAP account into Office 365.
This method is very time-consuming and not suitable for heavy migration.
Best Method: Use a Professional Tool to Import EML emails into Office 365
For users dealing with many EML files or requiring a safe and complete transfer, the easiest and most reliable option is a CubexSoft EML to Office 365 Converter tool. This automated utility provide many advance features like preview option, live conversion, multiple file formatting options like PST, PDF, MSG, MBOX, EMLX, etc. and many more features like this. If you want explore the free trial first before any payment the trial offers you export up to 25 emails per mailbox for free.
Benefits of Automated Tools:
- Directly upload EML files to Office 365.
- No need for Outlook or Gmail.
- Maintains folder hierarchy.
- Converts unlimited EML files at once.
- Preserves HTML formatting, metadata, and attachments.
- Works on both Windows and Mac.
- Allows selective migration date, sender, and subject.
- Supports shared mailboxes and admin accounts.
Conclusion
Migrating EML files to Office 365 has become a common need as more people shift from desktop email clients to cloud-based solutions. While manual methods exist, they are slow, limited, and not suitable for large or complicated mailboxes. If you want a smooth experience with complete data integrity, using the CubexSoft EML Converter tool is the most reliable choice. Whether you’re a Windows user or a Mac user, you can successfully import EML emails into Office 365 by choosing the right approach. With the proper tool, you can transfer emails, attachments, and folder structures in just a few clicks securely and efficiently.
