I used to get 1000's of spam email through our business email account every day. These are sent to an online ticketing system for customer support so filtering out the genuine emails from the junk was becoming a real pain in the arse.
I setup a gmail email account and redirected all of out business emails to our gmail account, from there they are redirected again to our ticketing system, but the nice thing is that Google has a brilliant spam filter which throws out all the junk before hand.
We still get the odd spam email slip through, but besides that out spam problems are solved.