Convert EML to RPMSG

Understanding EML and RPMSG file formats

EML files are standard email message files created by email clients like Microsoft Outlook, Windows Mail, and Mozilla Thunderbird. They store the content of an email, including attachments, headers, and formatting, in a plain text format based on the MIME RFC 822 standard.

RPMSG files are Rights-Protected Email Message files used by Microsoft Outlook and Exchange. These files are encrypted and use Microsoft Information Rights Management (IRM) to restrict actions such as forwarding, copying, or printing the email content. RPMSG files are typically generated when a user applies rights management policies to an email.

How to convert EML to RPMSG

Direct conversion from EML to RPMSG is not straightforward, as RPMSG files require integration with Microsoft’s IRM services. The process involves importing the EML file into Microsoft Outlook and then applying rights management to generate an RPMSG file.

Step-by-step conversion using Microsoft Outlook

1. Open Microsoft Outlook on your computer.
2. Import the EML file by dragging and dropping it into your Outlook inbox or using File → Open & Export → Open Outlook Data File.
3. Open the imported email message.
4. Click on File → Info → Set Permissions or Options → Permissions (depending on your Outlook version).
5. Select the desired rights management policy (e.g., Do Not Forward).
6. Send or save the message. Outlook will automatically convert the email to the RPMSG format and apply the selected restrictions.

Recommended software for EML to RPMSG conversion

• Microsoft Outlook (2016 or later) – The most reliable tool for applying IRM and generating RPMSG files.
• Microsoft Exchange Server – For enterprise environments, Exchange can automate rights management for emails.

There are currently no third-party converters that can directly convert EML to RPMSG due to the proprietary and secure nature of the RPMSG format.

Key considerations

• RPMSG files require a valid Microsoft 365 or Exchange account with IRM enabled.
• Recipients must have compatible software and permissions to open RPMSG files.
• Conversion is only possible within the Microsoft ecosystem due to security requirements.