If you have an eMail address, there is a good chance you are going to get spam.

http://en.wikipedia.org/wiki/Spam_%28electronic%29

Since our District is using Google Applications for Education, Google is our spam filter. This document attempts to explain how spam is handled.

There are basically 4 levels of spam (used by Google):

1. Messages you never see. These are messages determined by Google to be either made by viruses, known spammers, or messages that match certain criteria.
2. Messages that end up in your "Quarantine Report". These are messages that might be spam, but are dependant on your settings (available via your quarantine). By default, Google errs on the side of the possibility that the message might be real.
3. Messages that end up in your "spam" folder of your Google account. These are messages that passed most rules, but want your final approval.
4. Messages in your "In Box" that have passed multiple layers of testing, but want your final approval.

To explain these previous points:
 

1. For point 1, you will never see these messages. They do not come into your "In Box", they are not archived, and you never see them and you will never know you even were sent them.
2. For point 2, these are messages that *might* be spam, but they may also be real messages. Google is giving you the option of accepting the "deliver" or just ignoring them.
3. For point 3, these are messages that according to the rules Google set up, but might actually be "real" messages. If it is a real message, you have option of marking the message as "not spam" and Google will add that information to its database.
4. For point 4, you have the option of "marking" a message as spam. The more people that mark the same message as spam it is added to Google to enhance their spam filters.