RFC 8550: Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 4.0 Certificate Handling
In plain English — editorial summary, not part of the RFC
This document specifies conventions for X.509 certificate usage by Secure/Multipurpose Internet Mail Extensions (S/MIME) v4.0 agents. S/MIME provides a method to send and receive secure MIME messages, and certificates are an integral part of S/MIME agent processing. S/MIME agents validate certificates as described in RFC 5280 ("Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile"). S/MIME agents must meet the certificate-processing requirements in this document as well as those in RFC 5280. This document obsoletes RFC 5750.
Document record
- Document ID
- RFC8550
- Published
- April 2019
- Authors
- J. Schaad; B. Ramsdell; S. Turner
- Status
- PROPOSED STANDARD
- Stream
- IETF
- Area
- sec
- Pages
- 29
- Also known as
- —
- Obsoletes:
- RFC 5750
Topics
Standards lineage
This document is one revision in a chain of 4 RFCs, each formally replacing the one before it.
- RFC 2632 (1999)
- RFC 3850 (2004)
- RFC 5750 (2010)
- RFC 8550 (2019)
Related documents
Ranked automatically by shared keywords, IETF area and stream — not by editorial selection.
- RFC 8551Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 4.0 Message SpecificationUpdated
April 2019
- RFC 8823Extensions to Automatic Certificate Management Environment for End-User S/MIME CertificatesCurrent
April 2021
- RFC 9216S/MIME Example Keys and CertificatesCurrent
April 2022
- RFC 9788Header Protection for Cryptographically Protected EmailCurrent
August 2025
- RFC 7165Use Cases and Requirements for JSON Object Signing and Encryption (JOSE)Current
April 2014
- RFC 6025ASN.1 TranslationCurrent
October 2010
- RFC 5912New ASN.1 Modules for the Public Key Infrastructure Using X.509 (PKIX)Updated
June 2010
- RFC 5911New ASN.1 Modules for Cryptographic Message Syntax (CMS) and S/MIMEUpdated
June 2010
Also filed under
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The document record above — title, authors, date, status, stream, area, relationships, DOI and errata — is imported verbatim from the public RFC Editor index. The “in plain English” section is editorial: written by The metasystema editorial team, not part of the RFC. Where the two differ, the RFC text governs.
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