Open RPMSG File

Information, tips and instructions

How to Open RPMSG File

RPMSG files are used to deliver e-mails with Rights-Managed Email Object Protocol enabled. This protocol controls e-mail access and usage permissions. Instead of a plain text, e-mails via RPMSG files are sent with content encrypted and stored as encrypted file attachment.

RPMSG is used to send e-mails with rights management information attached. Rights management means user can specify certain restrictions to e-mail like disabling forwarding, restricting e-mail access rights only to specific users, restricting printing and copying. Permissions to rights restricted e-mail are enforced independently from the device where e-mail is received because rights management information is encoded in the e-mail itself. If you have Microsoft Outlook installed on a desktop or mobile device or use Outlook Web App (OWA) you can open RPMSG file transparently and without installing any additional software.

If Microsoft Outlook is not installed on the computer and you don’t use Outlook Web App (OWA) then Azure Information Protection viewer could be used to open RPMSG file attachments. Azure Information Protection viewer is available for download from the Azure RMS download page. In order to open a protected message client application may need to obtain a Use License from the server using Publishing License encoded in RPMSG file. Using a Use License client will be able to decrypt RPMSG message. Please note that only iOS and Android version of Azure Information Protection viewer supports Azure RMS cloud authentication and opening RPMSG file.

Data in RPMSG file is stored in a Compound File Binary format. This format allows storing multiple complex content objects in a single binary file. When application like Microsoft Outlook detects RPMSG file in e-mail it transparently decodes it and renders a message inside while honoring access rules specified inside.

Open RPMSG File on Windows OS

  • Try double clicking on a RPMSG file in Windows File Explorer.
  • If the RPMSG reading software is associated correctly then the file will open
  • If the file did not open you should install Microsoft Outlook
  • To open RPMSG file in Microsoft Outlook you need to launch it and then select File->Open... in the main menu
  • In the File Open dialog select RPMSG file and click "Open"

RPMSG files are transferred over e-mail or internet using application/x-microsoft-rpmsg-message multipurpose internet mail extensions (MIME) type.

Related Files
File Extension Info
Contact Us

RPMSG Quick Info
  Rights-Managed Email Object Protocol File
MIME Type
   application/x-ica
  application/x-microsoft-rpmsg-message
Opens with
  Microsoft Outlook
  Microsoft Outlook Web App (OWA)
  Azure Information Protection viewer