[Mimedefang] clamav vs clamd vs clamscan

[Cliff Hayes]

I am installing a new mail server on Scientific Linux 6.5.
What is the recommended way to install clam for mimedefang?
I have used binaries in the past but would prefer to use yum package 
unless binaries are better for some reason.
I have listed the available packages below ... clamd won't install via 
yum ... i get a message that it was obsoleted by clamav.
I see examples on the internet that mimedefang can fall back to clamscan 
if clamd fails but I don't know which packages to load to enable that.
Now that clamd is no longer available, what is the recommended course of 
action?

clamav-db.x86_64 : Virus database for clamav

clamd.x86_64 : The Clam AntiVirus Daemon

clamav.x86_64 : Anti-virus software

Thanks in advance.