Hello dtom,
Sorry for the trouble you are having receiving mail sent to [email protected], [email protected] and [email protected]`.
I have reviewed the logs and your messages are being blocked, probably not because of anything you specifically did. We do a variety of different types of throttling on inbound messages. We started to receive lots of messages from the email server eu-central-1.amazonses.com at 02:00 UTC on 2023-06-08. This is the same email server you are using and throttling has been applied to that email server.
If you were to send to a custom domain or private address there is a much higher throttling limit and you would not be having these mail delivery issues. Both of these features are included in our indie plan which is $18 per month.