File Types 
Outlook Restricted Permission Message
| Extension | .RPMSG |
| Developer | Microsoft |
| Format | Binary |
What is RPMSG File Format?
RPMSG file format is a type of Outlook email message with restricted permission levels, enabling the sender to control which recipients can open, read or edit their emails. This type of file is created when a user shares an item in Outlook, such as a contact, calendar, task or note. The file format is not readable by other email programs and must be opened in Outlook.
More Information
The RPMSG file format provides additional security features for Outlook users, ensuring that only authorized recipients can access sensitive data shared via email. It also allows the sender to limit how much information a recipient can view or edit.
Also, since the emails are encrypted, malicious hackers will have a hard time accessing confidential information contained within the emails since the file format is encrypted.
When sending an Outlook message with restricted permissions, the sender will be prompted to specify who should be allowed to open the message.
They can choose from several options, such as allowing all recipients to view the message, or restricting it to specific recipients. Additionally, the sender can specify whether recipients are allowed to reply, forward, delete or print the message.
How to Open and Edit RPMSG File?
STEP 1: To open an RPMSG file, open Microsoft Outlook, go to the Sent folder, select the RPMSG file and click Open.
STEP 2: To edit the contents of an RPMSG file, double-click on the file to open it in Outlook. Then right-click on the message and select Permissions. This will bring up a window where you can modify the permissions associated with the file.
STEP 3: If you are the sender of the RPMSG message, you can change the permissions. However, if you are the recipient, you cannot change the permissions.
How to Convert RPMSG File?
An RPMSG file can be converted by using a conversion utility that you obtain from a third-party vendor, which is available for free online.
Such utilities allow you to convert an RPMSG file into various other file formats, including:
- RTF File: Rich Text Format
- HTML File: HyperText Markup Language
- PDF File: Portable Document Format
- MHT File: MIME HTML File Format
- TXT File: Plain Text
- You can also convert RPMSG files into image formats such as PNG, JPEG, TIFF, GIF and BMP.