POP3
RFC 1939 Post Office Protocol - Version 3 → Update 1957, 2449, 6186, 8314
http://srgia.com/docs/rfc1939j.html
電子メール受信用プロトコル
MUAがメールサーバからメールをもってくるところ、他にIMAPがある
スパム避けなどでいろいろ対策もある
RFC 8997 Deprecation of TLS 1.1 for Email Submission and Access
RFC 8314 Cleartext Considered Obsolete: Use of Transport Layer Security (TLS) for Email Submission and Access → Update 8997
https://tex2e.github.io/rfc-translater/html/rfc8314.html
RFC 6856 Post Office Protocol Version 3 (POP3) Support for UTF-8
https://tex2e.github.io/rfc-translater/html/rfc6856.html
RFC 6186 Use of SRV Records for Locating Email Submission/Access Services
RFC 5034 POP3 SASL 認証メカニズム http://srgia.com/docs/rfc5034j.html
RFC 2449 POP3 Extension Mechanism https://tex2e.github.io/rfc-translater/html/rfc2449.html →5034 Update
RFC 1957 Some Observations on Implementations of the Post Office Protocol (POP3)
RFC 1734 POP3 AUTHentication command → 5034
RFC 1725 Post Office Protocol - Version 3 → 1939
関連
RFC 6530 Overview and Framework for Internationalized Email
https://developer.mozilla.org/ja/docs/Glossary/POP