i've an idea but i don't know as to how far this would work. I work part-time at a volunteering program for tsunami victims, and for all our incoming volunteers, upon arrival or upon assingment to a volunteer project, each one gets a free gmail address even tho they may alreay have a gmail address.
Why?
well simply 'cos, we wanted all our volunteers to use the volunteer gmail address we provide them with so thjat it wouldn't get mixed up with any of their ordinary emails, also they normally give out their volunteer gmails to NGOs and other aid organizations, sometimes we have spam coming off some orgs/individuals, these would go to the gmail volunteer addresses, and if they want to continue to receve and work with aid organizations after they have completed their volunteer projects they can use the mail forwarding option on gmail.
Now my idea is, use the above, except convert the idea to emplyers and employees, allow your employees to stay in touch via the same method, except that gmail can be access via their mobile version + pc-based version, after they've left the company its still theirs to keep and they can opt in to still recevive announcements from the company via the forwarding option.
How about that?