If you have an account at the Demography Lab then you also have an email address: username@demog.berkeley.edu. The reason for this address is not so that you can have yet another email address to use but rather so that we can let you know about things like server shutdowns and the availability of free beer. In other words, while the addresses exist, the infrastructure for sending and recieving email do not. When your account is initially setup, we configure it it forward any mail sent to username@demog.berkeley.edu to your current @berkeley.edu address. For historical reasons, we currently allow the world at large to send email to @demog addresses (to be forwarded on to @berkeley addresses) however, in the near future this will stop and the only use of your username@demog.berkeley.edu address is so that you can receive email from us.
And .. so that we can tell when you have graduated. When mail starts to bounce... we'll know you're gone.