EML is a commonly used file format for storing individual email messages, supported by email clients like Windows Live Mail, Outlook Express, Thunderbird, eM Client, and others. However, as businesses increasingly shift to cloud-based platforms like Office 365, users often need to upload or migrate their EML files into Office 365 mailboxes for centralized access, better data management, and enhanced security. This blog explains how to add EML files to Office 365, outlines the reasons behind the migration, and offers both manual and professional solutions, including a smart alternate solution.

Microsoft Office 365 is a cloud-based productivity platform that includes Outlook, Word, Excel, OneDrive, Teams, and more. Unlike EML files that reside on a local system and are client-specific, Office 365 provides web-based access to emails, greater scalability, and better collaboration features. Adding EML files to Office 365 enables users to consolidate old emails into their current Office 365 mailbox, ensuring continued access to past communication without relying on outdated desktop email apps.

Why Add EML Files to Office 365?

There are several reasons users move their EML files to Office 365 -

• Centralized Email Management – Store all old and new emails in one cloud-based mailbox.
• Platform Independence – Access emails from any device or location via web login.
• Improved Data Security – Benefit from Microsoft’s advanced encryption and protection.
• Email Backup & Retention – Comply with organizational backup and archiving policies.
• Discontinuation of Desktop Clients – When users stop using Thunderbird, WLM, etc., they prefer shifting old emails to Office 365.

How to Add EML Files to Office 365 by Manual Method

Unfortunately, there’s no direct manual method to import EML files into Office 365. However, a workaround exists using Outlook and IMAP configuration -

• Add Office 365 account to Outlook: Open Outlook and configure your Office 365 account via IMAP or Exchange.
• Import EML into Outlook - Drag and drop EML files into an Outlook folder.
• Sync with Office 365 - Once added, Outlook syncs the folder and messages to your Office 365 account.

While this method works, it’s very limited and time-consuming, especially for bulk migration.

Drawbacks of the Manual Method

• No Batch Support – Drag-and-drop must be repeated for every folder or set of EML files.
• Time-Consuming – Manual importing is slow, especially for large volumes.
• No Filters – You can't selectively migrate EML files by date, subject, or sender.
• Risk of Data Loss – Improper handling may lead to missing attachments or broken formatting.
• Requires Technical Knowledge – Non-technical users may find configuring Outlook and syncing difficult.

Better Alternative - How to Add EML Files to Office 365

To overcome the limitations of manual processes, the BitVare EML Converter for Mac & Windows  provides a smart, secure, and automated way to add EML files to Office 365.

Key Features

• Direct Migration to Office 365 using valid login credentials.
• Bulk Upload of EML Files or Folders at once.
• Selective Export with Advanced Filters (by date range, subject, sender, etc.).
• Preserves Attachments & Folder Structure during migration.
• Supports All EML Sources like Windows Live Mail, Thunderbird, eM Client, etc.
• Mac & Windows Compatible with a clean, user-friendly interface.

This tool eliminates the need for Outlook, complex configurations, or repetitive manual steps. Simply load your EML files, enter your Office 365 account details, and start the migration with just a few clicks.

Conclusion

Adding EML files to Office 365 is a common requirement when consolidating emails from legacy systems into modern cloud platforms. While manual methods are possible, they are far from efficient, especially for bulk or selective migrations. If you're looking for a reliable, accurate, and user-friendly way to import EML files to Office 365, the EML to Office 365 tool for Mac & Windows is the ideal solution. Try the free demo today and experience seamless EML to Office 365 migration with minimal effort.