.P7M File Extension

S/MIME Email Message

Developer RSA Data Security
3.0  |  138 Votes

What is a P7M file?

A P7M file is an S/MIME encrypted or signed email message. Most commonly, P7M files appear in web-based email clients, when they attempt to show an S/MIME encrypted message. Instead of showing the encrypted message, these programs show an empty message with a P7M attachment.

More Information

Secure/Multipurpose Internet Mail Extensions (S/MIME) is an email encryption and digital signature standard. It is used to encrypt sensitive messages and verify senders' identities. For example, businesses might use S/MIME encryption to protect confidential medical or financial information sent via email.

To use S/MIME, you must install an S/MIME certificate and link it with your email client, such as Microsoft Outlook or Apple Mail. If your email client is not linked to a valid S/MIME certificate, messages encrypted or signed using S/MIME will contain a P7M file. Most often, this file is named smime.p7m.

Common P7M Filenames

smime.p7m - The default name for P7M files that arrive as email attachments. They usually contain encrypted email content.

How to open a P7M file

You can open P7M files in Cryptigo p7mViewer (Windows). If your P7M file contains an email that was only signed using S/MIME, you can open the file without a private key. If your P7M file contains an email encrypted using S/MIME, you need the private key used to encrypt the file.

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Programs that open P7M files

Verified by FileInfo.com

The FileInfo.com team has independently researched the S/MIME Email Message file format and Mac and Windows apps listed on this page. Our goal is 100% accuracy and we only publish information about file types that we have verified.

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