9 rfc2183.txt The Content-Disposition Header Field
10 rfc2342.txt IMAP4 Namespace
11 rfc2359.txt IMAP4 UIDPLUS extension
12 rfc2487.txt SMTP Service Extension for Secure SMTP over TLS
13 rfc2554.txt SMTP Service Extension for Authentication
15 rfc2822.txt Internet Message Format
16 rfc2980.txt Common NNTP Extensions
17 rfc3156.txt MIME Security with OpenPGP