We run an Exchange 2007 server, with around 200 users. We have a number of domains registered, which we currently receive email for. Some are old, and we are planning to abandon them, let the registration lapse, kill the MX records & remove then from the list of accepted domains. We have let users know, and are waiting a few months so that they can inform senders.
Someone has suggested we should send back a response to anyone who tries to send email into our old domains, letting them know to use a new one.
ie. if Fred@hotmail.com sends an email to Bill@ourolddomain.com, we would like Exchange to automatically send a response back saying "@ourolddomian.com is slated for retirement, can you please send future email to %username%@ourcurrent domain".
Any ideas how to achieve this?