> Am 15.04.2022 um 08:49 schrieb Fourhundred Thecat <400the...@gmx.ch>: > > Are there any legitimate cases where "to:" might be missing?
RFC 5322 says: "The only required header fields are the origination date field and the originator address field(s).", i. e. the "Date:" and the "From:" header field. <https://datatracker.ietf.org/doc/html/rfc5322#section-3.6> I have sent this answer without any address in the to header field.
