Spam is the electronic version of "junk mail." The term spam refers to unsolicited, often unwanted, email messages. Spam does not necessarily contain viruses. Valid messages from legitimate sources could fall into this category.
Don't give your email address out arbitrarily
Email addresses have become so common that a space for them is often included on any form that asks for your address.
Check privacy policies
Be aware of options selected by default
When you sign up for some online accounts or services, there may be a section that provides you with the option to receive email about other products and services. Make sure to change the settings.
Many email programs offer filtering capabilities that allow you to block certain addresses or to only allow email from addresses on your contact list.
Report messages as spam
Reporting messages as spam or junk helps to train the mail filter so that the messages aren't delivered to your inbox.
Don't follow links in spam messages
If you click a link within an email message or reply to a certain address, you are just confirming that your email address is valid. Unwanted messages that offer an "unsubscribe" option are particularly tempting, but this is often just a method for collecting valid addresses that are then sent other spam
Disable the automatic downloading of graphics in HTML mail
Disabling HTML mail entirely and viewing messages in plain text also prevents the automatic download of graphic files and track if you opened your email
Consider opening an additional email account
Create a secondary email account to protect your primary email account from any spam that could be generated
Use privacy settings on social networking sites
Consider hiding your email account or changing the settings so that only a small group of people that you trust are able to see your address. Be cautious about which applications you choose to use.
Don't spam other people
Don't forward every message to everyone in your address book, and if someone asks that you not forward messages to them, respect their request.