Out of interest, were you using a dedicated IP address with SES? As I understand it you've doomed to deliverability issues unless you have your own IP address which nobody else is sending from.
That said, by no means am I claiming that email deliverability is easy!
If you’re a small-time sender, having your own IP address is probably actually a bad thing, because now the IP address never builds up enough positive reputation.
That said, by no means am I claiming that email deliverability is easy!