An Internet Message Format email message conforming to RFC 2045 (https://www.ietf.org/rfc/rfc2045.txt), specifically containing MIME-Version and Content-Type header fields, in addition to header fields 'To', 'From', and 'Date' as described in RFC 822 (https://www.ietf.org/rfc/rfc822.txt).
04/2024 (v.118): Max offset of one BOF sequence increased to 20000. Submitted by Archives New Zealand; 07/2024 (v.119): Internal signature BOF sequence modified to allow for t or T in 'Content-(t|T)ype:'. Submitted by the National Library of Australia.