exim virus scanning and spam scanning

[hanasaki <hanasaki@hanaden.com>]

whats the difference between amavis-ng and milter and amavisd-new?   are 
some going away?  which one do you use for what? or clamscan directly? 
how can virus scanning be added?  clamscan and spam Spam assassin seem 
to be the norms from googling.  the configuration files to integrate 
with exim are befuddling.

the plan is too hook a virus scanner into exim4 from sarge.  any 
thoughts are appreciated.  A copy of someone's working exim4 config 
would be great!

how does one integrate the following with exim?  And which do you folks 
recommend for what reasons?
		SPAM
	Spamassassin
	bogofilter

		VIRUS
	amavis
	amavisd-new
	clamscans

thanks!