SES denied production access without a reason

I am working in a college research organization and developing health-related apps for youths. We are applying for SES production access because we would like to send health assessment reports to our users.

We are plan to send 1-100 emails daily and only send emails when our users request it. We had a detailed plan on handling bounce and complaints.

We got denied without a reason and AWS support told us they will no longer respond to our case. (CASE 9697186941) We are not asking to increase the limit, all we want is to remove out from the sandbox environment. I understand that there are people abusing the system but I feel this is unfair to us.

I've tried to use the AWS workmail but I don't see an SMTP option there. I also tried to set up an SMTP server on EC2, but AWS block port 25.

We try to stick with AWS if possible, does anyone have suggestions? Thank you