Many people make the mistake of maintaining just one E-Mail account and use the same E-Mail account is for personal messages, business messages, sign up for subscriptions and other online services. The likelihood of a phishing* attack or a hacker installing malicious files increases because the number of spam messages is greater when all E-Mail from various people and agencies land in the same E-Mail account. As a result, the user has to be on guard at all times.
A simple way to address this problem is to use different E-Mail accounts for different purposes: personal, business, online mailing lists, and another for when you go shopping online. If you do not want too many E-Mail accounts, you should at least have a E-Mail account where everything besides work, friends and family letters are sent. Chances are that any spam that you might receive will mostly be concentrated on this particular E-Mail account. Be extra careful when reading mails received on this E-Mail account and you reduce your chances of a phishing attack or getting hacked.
*According to Wikipedia, phishing is the criminally fraudulent process of attempting to acquire sensitive information such as usernames, passwords and credit card details by masquerading as a trustworthy entity in an electronic communication.