e-mail addresses of civilians working for the US military

[fides]

Does anyone know if there is a standard format for e-mail addresses given to civilians employed by the US military on a military base. In this case we the civilian works for a secret project under the USAF (the project is secret, the fact he works with the military, not so much). Would the character have a .mil e-mail address? Would this be in the format username@usaf.mil or would the be something in the address which would indicate either his status as a civilian or the perminent base he is (theortically) working at? Or, for security, would he have a totally non-military email?

This is approximately present day US.

I've tried googling for this but the web is more interested in selling me a military email address than giving me useful information.

Thanks.