Please explain in detail, we need more information to help. Firstly you mention difficulty/inability to enter sites and then you mention 'I need email...'
Possibly two different things, please explain, what error messages, etc. help us to help you.
Have you recently installed avast 4.6 or had you updated from an earlier version?
What browser are you using?
What email program?
Is your email web based, e.g. you use your browser to view it?
Do you have a firewall, if so which one?
Why do you think it is cookie rejection that is causing the problem?
I think you can see we need help to help you.