not for greylist.(could be optional like bill said)
smtp auth + tls (maybe TLS can be optional if ppl think so).
I think QMAILQUEUE patch works fine for SA or CLAM, i use a small C prog that calls a script that runs SA and CLAM, i don't need no qmailscanner or qscan, there is no need to add extra support for it hence vpopmail is also getting support for that.
http://www.arda.homeunix.net/store/qmail/ is now the old qreqex patch unixpimps, but unixpimps patch has so many bugs. qmail bounce patch by Frank Denis. (allows you to set maxsize of bouncing mails, helps to stop abuse).
/R
