Yahoo is getting ready to reuse unused YahooIDs and the email addresses associated with them. Beginning today, Internet users can request up to five email addresses. If the address is available to be recycled, meaning that it hasn't been used in more than a year, it will be doled out to the first user who requested it. At this point, users can only get one recycled address. Yahoo says that it is implementing new security measures in a move to prevent identity fraud. This includes a new email header that verifies account creation dates which prevents a user from accessing old data associated with the address.