rfc977.txt NNTP rfc1939.txt POP3 rfc2045.txt MIME 1 rfc2046.txt MIME 2 rfc2047.txt MIME 3 rfc2048.txt MIME 4 rfc2049.txt MIME 5 rfc2183.txt The Content-Disposition Header Field rfc2342.txt IMAP4 Namespace rfc2359.txt IMAP4 UIDPLUS extension rfc2487.txt SMTP Service Extension for Secure SMTP over TLS rfc2554.txt SMTP Service Extension for Authentication rfc2683.txt IMAP4 Implementation Recommendations rfc2821.txt SMTP rfc2822.txt Internet Message Format rfc2980.txt Common NNTP Extensions rfc3156.txt MIME Security with OpenPGP rfc3501.txt INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1