If you have received an e-mail like this, DO NOT RESPOND to it.  It is what is known as as phishing scam, an attempt by a third party to obtain your authentication information and hack your account.  There has been a recent significant uptick in these, mostly originating in foreign countries such as Iran and Bahrain.  We do not use a password aging system here.  My personal experience with such systems is they cause more problems than they are worth.  If passwords are poorly chosen, a system that forces you to choose a new one on the spot is not likely to result in stronger passwords.