There are 3 issues here.
Issue #1 - Clear out your mailbox or increase the quota. I have a feeling the reason it is full is probably because of the issue with Amazon emails marked as Phishing by Avast version 8.
Issue #2 - Why is it marked Phishing? I can’t believe you have amazon.com as a phishing email. In Avast version 7 it didn’t, it does when you upgrade to 8.
Issue #3 - I have added amazon to the safe senders list, but everytime I order something it still marks the order confirmation as Phishing. How do I fix that?