Open RPMSG File

Information, tips and instructions


Open RPMSG File

RPMSG file extension is a way of enforcing Rights-Managed Email Object Protocol which controls e-mail access permissions. Instead of a plain text, e-mail is sent by Microsoft Outlook with an e-mail content encrypted and stored as RPMSG file attachment.

RPMSG is used to send e-mails with rights management inside. 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 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 (https://portal.azurerms.com/#/download). 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 Use License client will be able to decrypt RPMSG message.

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.

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

Get more information about how to open RPMSG file.

Also check how to open CAJ file and open NOMEDIA file on Open File Database.

If you are not able to open file with certain file extension make sure to check if extension for the file is correct. It is possible that information in the file doesn't match file extension.

File Extension Info

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