Is browser based email scanning possible?

It is unclear to me, if the Norton Internet Suite 2012 product can in fact actually scan email messages that are not present on the user’s computer, but are being viewed via a web browser at a hosted site.  For example: I I ready my AOL email via browser while traveling, I never download the email, only view it remotely. Am I able to have the remote email message and attachment scanned before I open them remotely.  Ok don't laugh, it sounds simplistic and very newbie I agree, but I need a detailed reason this is not possible.  I currently do not run any independent email specific applications. Am I relying on the Email host to provide the scanning that I desire? or is it on me to do this security task?  Thank you in advance for your patience and responses.