associate an account email with user's role (not user)

In my organization, a user can wear different hats at the same time (e.g. Vice President on Administrative side, and Lieutenant on firefighting side). When acting as VP, he needs to send/receive emails using the VP email address (e.g. mailto:email address removed for privacy reasons), whereas when acting as Lieutenant, he should use that email address (mailto:email address removed for privacy reasons). And all members of our organization have their own individual email addresses (e.g. for above: mailto:email address removed for privacy reasons). Over time, an individual might get promoted on the firematic side or the administrative side and so may use different emails. 

Is there a (simple) way to associate an email address with the user's role(s) rather than with  a user directly?

This way we could, for example, add or remove that role from a user (e.g. remove lieutenant from their role(s), and add the captain role after a promotion) so that that user automatically gains access to that email address (for company correspondence) AND all emails sent/received from the previous captain (in their position) and remains in that "pseudo-role-account?"

Right now, I've set it up so that everyone has their own email addresses (e.g. mailto:email address removed for privacy reasons) and then add aliases to each as needed (e.g. mailto:email address removed for privacy reasons). Then re-assign these "role-based" aliases as needed (e.g. when folks leave, get promoted). This feels quite cumbersome and inefficient.

Is there a best-practice method for this?