Configure banned extensions. Scan zipfile option with test case.

milter.cfg

@@ -28,6 +28,8 @@ log_headers = 0
 ;[defang]
 # do virus scanning on attached messages also
 scan_rfc822 = 1
+# do virus scanning on attached zipfiles also
+scan_zip = 0
 # Comment out scripts in HTML attachments.  Can be CPU intensive.
 scan_html = 0
 # reject messages with asian fonts because we can't read them
@@ -45,6 +47,11 @@ porn_words = penis, breast, pussy, horse cock, porn, xenical, diet pill, d1ck,
 	valium, rolex, sexual
 # reject mail with these case sensitive strings in the subject
 spam_words = $$$, !!!, XXX, FREE, HGH
+# attachments with these extensions will be replaced with a warning
+# message.  A copy of the original will be saved. 
+banned_exts = ade,adp,asd,asx,asp,bas,bat,chm,cmd,com,cpl,crt,dll,exe,hlp,hta,
+	inf,ins,isp,js,jse,lnk,mdb,mde,msc,msi,msp,mst,ocx,pcd,pif,reg,scr,sct,
+	shs,url,vb,vbe,vbs,wsc,wsf,wsh 
 
 # See http://bmsi.com/python/pysrs.html for details
 [srs]