Has some nice anti spam features (see below) - once it goes final (presently in beta) will there be an update for FC6 ? Some of the useful stuff: Try to deal with open HTTP proxies that are used to send spam by recognizing some commands from them. If the first command from the client is GET, POST, CONNECT, or USER, then the connection is terminated immediately. New PrivacyOptions noactualrecipient to avoid putting X-Actual-Recipient lines in DSNs revealing the actual account that addresses map to. Patch from Dan Harkless. CONFIG: New FEATURE(`require_rdns') to reject messages from SMTP clients whose IP address does not have proper reverse DNS. Contributed by Neil Rickert of Northern Illinois University and John Beck of Sun Microsystems. CONFIG: New FEATURE(`block_bad_helo') to reject messages from SMTP clients which provide a HELO/EHLO argument which is either unqualified, or is one of our own names (i.e., the server name instead of the client name). Contributed by Neil Rickert of Northern Illinois University and John Beck of Sun Microsystems. CONFIG: New FEATURE(`badmx') to reject envelope sender addresses (MAIL) whose domain part resolves to a "bad" MX record. Based on contribution from William Dell Wisner.