This is great. I tried a similar approach but couldn't use it as a transactional email server because of this (taken from OP's readme):
> By default, you can't send emails to unverified addresses. If you'd like to be able to send (as opposed to just receiving), you'll need to reach out to AWS to remove this limitation from your account.
I reached out AWS to remove this limitation but they refused my request 3 times claiming that my use case would impact the deliverability of their service.