According to Tech Guy Labs:
“The longer you use an email, the more SPAM you will get. The easier your email is “guessable” by spambots, the more spam you’ll get. The more listserves you’re with, the more SPAM you’ll get. Leo, for instance, gets over a million spams a month!
Leo’s 3 stages for Spam management:
2) Use Spam Assassin on your server.
3) Finally, a local solution like Mail Washer.”
Another option, when using services like Hotmail or Yahoo, in recent years, have spam-catching services that seem to catch most, if not all, spam or junk email. You can also have the junk email filter spam to specific folders. Microsoft Outlook has similiar options. You can also use a Junk Email Senders List, and filter to specific folders as well.
In Outlook, right-click email, choose “Junk E-Mail”, and “Add to Blocked Senders List”. From that point on, Outlook filter those emails to the Junk Mail folder. You can also right-click messages and “Create a Rule”, so the message is automatically filtered to the folder you designate.