S/MIME
S/MIME (Secure/Multipurpose Internet Mail Extensions) is a standard for public key encryption and signing of MIME data. S/MIME is on an IETF standards track and defined in a number of documents, most importantly RFCs 3369, 3370, 3850 and 3851.
Cost / License
- Free
- Open Source
Application type
Platforms
- Mac
- Windows
- Linux
- Online
- Android
- iPhone
- Blackberry
- Chrome OS
- Android Tablet
- Windows Phone
- iPad
Features
Properties
- Privacy focused
- Security-focused
Features
- End-to-End Encryption
S/MIME News & Activities
Recent activities
S/MIME information
What is S/MIME?
S/MIME (Secure/Multipurpose Internet Mail Extensions) is a standard for public key encryption and signing of MIME data. S/MIME is on an IETF standards track and defined in a number of documents, most importantly RFCs 3369, 3370, 3850 and 3851.
It was originally developed by RSA Data Security Inc. and the original specification used the IETF MIME specification with the PKCS#7 secure message format. Change control to S/MIME has since been vested in the IETF and the specification is now layered on Cryptographic Message Syntax, an IETF specification that is identical in most respects with PKCS #7.
S/MIME functionality is built into the majority of modern email software and interoperates between them.




