… in RFC 2634 , RFC 5035 , RFC 5652 , RFC 5750 , and RFC 5751 [ SMIMEv3.2 ]. - [ RFC2311 ] also has historical information about the development of S/MIME. Schaad, et al. Standards Track [Page 8] RFC 8551 S/MIME 4.0 Message Specification April 2019 1.5 . Changes from S/MIME v3 to …

…[ RFC2047 ], [ RFC2049 ], [ RFC4288 ], and [ RFC4289 ]. [ SMIMEv2 ] refers to [ RFC2311 ], [ RFC2312 ], [ RFC2313 ], [ RFC2314 ], and [ RFC2315 ]. [ SMIMEv3 ] refers to [ RFC2630 ], [ RFC2631 ], [ RFC2632 ], [ RFC2633 ], [ RFC2634 ], and [ RFC5035 ]. [ SMIMv3.1 ] refers to [ RFC2…

…6 The Internet and the Millennium Problem (Year 2000) June 1999 +=+=+=+=+= File rfc2311 .txt +=+=+=+=+= 'yy' on a line without 'yyyy' found at line 269: 267: Sending agents MUST encode signing time through the year 2049 267(continued): as 268: UTCTime; signing times in 2050 or la…