In RFC 822 a destination address was required to appear in the headers, section C.3.4. reads "A message must contain at least one destination address field. 'To' and 'CC' are required to contain at least one address." In RFCs 2822 and 5322, section 3.6. in both, they read: "The only required header fields are the origination date field and the originator address field(s)."
I'm interested in what the reasoning was behind this change. I know the IETF has mailing list archives and meeting minutes, but if that's documented in the mailing lists I'm having a hard time finding it searching the archives.
