Another method for protection
its a good idea not to set the email program to automatically do a preview of the message when you click on the header on the list in the inbox.
also, what has worked for me is to have multiple email accounts, each tied to a particular service, ie bank accounts, credit cards, utilities, etc... now a days, there is no limit as to how many email accounts people can have. so why not take advantage of it and set up a system.
in my system, if i see an email header in my hotmail inbox that looks like it pertains to the bank, but i had actually set up my bank account with an email address via my isp email account, then its easy to see that the message in the hotmail can be unquestionably deleted.