Hey,
Google is pretty good at detecting junk emails but sometimes it gets it wrong, when that happens do this:
Go to gmail on either your phone or computer.
Phone: inside the gmail account press the menu key and goto lables. Select the "Spam" label. All emails that Gmail thought were junk are kept in here for 30 days before being automatically deleted forever. Click the email you want to see and press remove label at the bottom (note I'm on 2.2 froyo) if thats not in your version hit menu then change labels send it to the inbox or what ever you need to do.
Web Browser: Go to your gmail account. On the left hand side is a column containing "labels" you should see drafts, sent mail, all mail and others, you want to click "spam". If spam is not visible click the more button and you should see it there. Go into the message you want to view and click "not spam" on the bar above the email. you may also use the other features to add other labels etc from the bar.
