We currently can label an email address as "Work," "Personal," or "Other."

I suggest a fourth label to indicate an expired, no longer current or invalid email address that we could use when a Contact changes employers.

For example, when Suzie Q leaves Acme Widget Company, suzieq@acmewidget is no longer an email to reach this person, nor is it a valid email to reach anyone at Acme Widget Company.

However, I do not want to delete this email address because I want to keep all of the correspondence associated with it.

I'd like to keep those messages associated with the Company and possibly (which means, conditionally, as I see fit) with Suzie Q herself.

Flagging the email as "Other" does not communicate clearly that this is NOT a valid address for Suzie Q. What happens when a co-worker has to send email to Acme Widget Company but does not know that Suzie Q is no longer there?

If we had a label "Former" (or something indicative of the status of the email address), we could add Suzie Q's former email address to the Company record, thereby preserving all correspondence with that email address and also preventing emails from being inadvertently sent to that address.