Got email? Then you've seen more than your share of unwanted messages, otherwise known as spam. But what you get in your inbox just scratches the surface. Behind the scenes, filtering services have spared you countless folders-worth of spam.

For incoming email at MIT, Information Systems and Technology (IS&T) uses Symantec Messaging Gateway (SMG). Here's a look at how the Symantec service works and ways to customize it.

SMG first blocks email from known bad senders before it reaches MIT's email infrastructure. (Over 90% of the email SMG blocks is the result of preventing the spammer's mail server from even connecting to MIT.) To ensure effectiveness, Symantec's Global Intelligence Network continually responds to new spam threats.

SMG next identifies spam and suspected spam through a series of tests; it then sends this email to the Spam Quarantine Server. If you have an MIT email address, you'll get a daily quarantine summary in your inbox from SpamQuarantine@mit.edu.

If you think an email in your quarantine summary is legitimate, you can view it and opt to release it. It will then be transferred to your inbox. If you do nothing, Symantec automatically deletes messages in your Spam Message Quarantine after 14 days.

Another option is to log in to SMG to view your current list of quarantined messages. Here you can read the full text of these messages, release any that are legitimate, and quickly delete the rest using the Delete All button.

To read the full article, which also includes tips about Bad and Good Senders lists and Outlook's Junk feature, visit the IS&T News page.