https://app.knowbase.one/vault/rfc/docid/8380
RFC0771: Mail transition plan
Network Working Group V. Cerf (ARPA) Request for Comments: 771 J. Postel (ISI) September 1980 ...
Network Working Group V. Cerf (ARPA) Request for Comments: 771 J. Postel (ISI) September 1980 ...