When a user deletes an address, hard bounce it and prevent future users from getting the same address

[groovecoder]

When a user deletes an address, we still need to:

• [x] Prevent any future addresses from using the same localpart
• [ ] Hard-bounce any messages sent to the address

To do this AND still delete our record of the plaintext email address:

1. [x] Insert the deleted address into a new emails.deleted_addresses table
2. [x] Delete the address from the emails.relay_address table
3. [ ] Hard bounce all emails sent to unknown addresses
   • Call CreateReceiptRule with BounceAction for the recipient.

[groovecoder]

SocketLabs may not have an API to bounce emails sent to unknown/deleted addresses.

Amazon SES has a CreateReceiptRule API so we could create bounce rules for addresses that are deleted.