Two emails for one user

As one of the many users @downey was referring to, I’d love to see something like this in my Discourse preferences:

In our case, email addresses are not editable in Discourse, since they’re provided by SSO. If we weren’t using SSO, then editing alternate emails could be done via a text area with one address per line.

For us, the primary need is to accept new posts via email from alternate email addresses, so users don’t need to worry about which account they’re using to email the community.