How to open a .RPMSG file online
No mail account and no extra software to install.
Pick your .RPMSG file
Drag it in or click to choose it. It opens here in a moment.
Read it safely
The message opens in a locked-down view: scripts never run, and remote images often used for tracking stay blocked until you allow them.
Check and save
Download attachments, read the full headers, and see every server the message passed through, with SPF, DKIM and DMARC results.
About .RPMSG files
What a .RPMSG file is, and what's inside it.
An RPMSG file (almost always named message.rpmsg) is an encrypted, rights-protected email container created by Microsoft Outlook when the sender applies Information Rights Management (IRM). You cannot open it like a regular attachment; it decrypts only for the intended recipient. Open the original email in Outlook signed in with the recipient address, or click the Read the message link in the email body to view it in a browser portal.
Programs that open .RPMSG files
| Full name | Restricted Permission Message |
|---|---|
| Developer | Microsoft |
| First released | 2003 (Windows Rights Management Services / Outlook 2003 IRM); today part of Microsoft Purview Message Encryption |
| Category | |
| MIME type | application/x-microsoft-rpmsg-message |
| Signature | 76 E8 04 60 |
Related viewers
Open the attachments you find.
Is it safe to open a suspicious .RPMSG file here?
Safer than in a mail client: the message runs in an isolated frame with scripts disabled, remote images and trackers are blocked until you allow them, and attachments are never opened automatically.
How can I tell if an e-mail is fake?
Look at the Message info panel. We show the SPF, DKIM and DMARC results recorded by the receiving server, warn you when the Reply-To address differs from the sender, and list every server the message passed through.
Can I open a Gmail or Thunderbird mailbox (.mbox)?
Yes. Drop the .mbox file and you'll get a searchable list of every message. Click one to read it.
Why does my MSG file show plain text only?
Some Outlook messages store their formatting only as compressed RTF. We show the text today; full RTF formatting is coming soon.
Can I open .pst or .ost files?
Not yet. Outlook data files are on our roadmap. Meanwhile you can export single messages from Outlook as .msg and open them here.
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