Dr. Web is a Plesk add-on virus scanning program that is an optional program that when activated has additional licensing costs associated with it. We have decided to not license the Dr. Web virus scanning software as we have chosen a more comprehensive solution for Anti-Spam and Anti-Virus email filtering.
You can find more information regarding the optional Anti-Spam and Anti-Virus Email Filtering Service we offer at http://forum.schmolie.com/index.php?showtopic=1899.