Our spam blocker currently blocks over 35,000 emails per day. About 1% still make it through. If you do the math, that's still a lot of emails (350) that make it to the end user every day. The good news is that the people that make the anti-spam device we use update it daily so it gets smarter every day.
Steps you can take in your Google Account:
To remove spam from your inbox:
Select the message you'd like to report. Click the "Spam" button in the toolbar above your message list.
(If you have the message open, you can also report it as spam by using the same button).
To remove spam forever:
Click the "Spam" link along the left side of any Gmail page. (If you don't see "Spam" along the left side of your Gmail page, click the "More" drop-down menu at the bottom of your labels list). Select the messages you'd like to delete and click "Delete forever." Or delete everything by clicking "Delete all spam messages now."
The more spam you mark, the better our system will get at weeding out spam messages. If you accidentally mark a good message as spam, select the message and click "Not Spam" at the top of the message. If you marked it as spam, you can also immediately click "Undo" afterwards to recover the message.