Multiple e-mail support?

Is it possible to include multiple e-mail addresses that use different GPG keys?

Example:

```
Address: admin@example.com
Key ID: 0xFFFFFFFF
```

and

```
Address: jdoe@example.com
Key ID: 0x00000000
```

Verification can happen by signing a message with the actual PGP key and then click a link sent. Also, there is a need for an additional layer of confirmation just in case it's a mailing list and someone claims it.
This also needs a way to take the trust from the server and put it to public data. Maybe a GPG Key Sign of the second address with the primary and vice versa?

No files, tests, or entry points are identified in the issue. First clarify the scope and trust model for multiple addresses, distinct GPG keys, signed verification, and mailing-list confirmation; the work is done when an agreed implementation plan and acceptance criteria exist.

Written by the indexing model from the issue text.