What is your OS ?
What is your email program ?
Or you downloading email from yahoo or hotmail/msn, e.g. what is the domain name of your email server/s (after the @ in the email address) ?
right click the avast icon, select Start avast! Antivirus, Menu, Help.
Or you could create a desktop shortcut, C:\Program Files\Alwil Software\Avast4\ENGLISH\HELP\help.chm