Well known addresses

We should have a few well-known addresses to exist for users.

• example!: An example user. All mail sent to this address will be directly deleted. Useful for examples, code snippets, demos, etc
• you@example!: An example user at an example organization. All mail sent to this address will be directly deleted. Useful for examples, code snippets, demos, etc.
• hello!: This will send back an email with a hello response. Useful for testing connectivity and accounts.
• hello@bitmaelum!: This will send back an email with a hello response. Useful for testing connectivity and accounts (not functional yet)