Regarding Foe email: If someone you've foed takes it upon themselves to keep contact with you via pm, you can adjust your mail settings to delete their email as soon as it arrives, therefore keeping your email clean of unwanted trash.
Go to User Control Panel (upper left corner of any forum page)
click on "Private Messages" tab
click on "Rules, Folders, & Settings" tab on the left
under "Add New Rule", next to "if", pick "sender" from dropdown menu, click next
pick "is" from next dropdown, click next
enter offending username to blank field, click next
pick "delete message" from next dropdown, click "add rule"
All future emails from that person will immediately be deleted without you ever having to see them, and without them taking up any space.