null envelope sender

[barry kwok]

I don't know whether this is a mailscanner or postfix problem (or client si=
de problem).=0A=0AWhen checking the maillog, I found that some clients (loc=
al senders) or outside MTAs (normal emails) have null envelope sender. They=
 comes in random. The same clients will have normal envelope sender sometim=
es. =0A=0AThis may not a problem before I add watermark features in MailSca=
nner. But those normal null envelope sender will have chance to become spam=
 emails after I adding some scores to null senders.=0A=0ARegards,=0ABarry=
=0A=0A=0A      =A5X=AEt=A9=CE=A5h=AE=C8=B9C=AE=C9=A1A=A7A=A5i=A5H=C0H=AE=C9=
=C0H=A6a=A5=CE=A5=FE=B7s=AA=BAYahoo! Messenger =BA=F4=A4W=AA=A9=B8=F2=A7A=
=AA=BA=AAB=A4=CD=A7Y=AE=C9=B3q=B0T=A4=CE=ACd=B8=DF=B9=EF=B8=DC=B0T=AE=A7=AC=
=F6=BF=FD! =BD=D0=ABe=A9=B9 http://hk.webmessenger.yahoo.com/ =A5=DF=A7Y=A8=
=CF=A5=CE! =0A