Postfix Restriction List

List of Postfix:

smtpd_client_restrictions Reject all client commands
smtpd_helo_restrictions Reject HELO/EHLO information
smtpd_sender_restrictions Reject MAIL FROM information
smtpd_recipient_restrictions Reject RCPT TO information
smtpd_data_restrictions Reject DATA command
smtpd_etrn_restrictions Reject ETRN command

REFERENCE:
[IRBS] http://www.irbs.net/internet/postfix/0405/0297.html
[PSFX] http://www.postfix.org/SMTPD_ACCESS_README.html#lists