How to remove email sending limitations

Hello.

As mentioned in the comments in the document below, we do not recommend applying to remove the restriction on port 25 in AWS because the hurdles to approval are high.
https://repost.aws/knowledge-center/ec2-port-25-throttle#COV8eEPhyHTmGB3TZNPJyPFg

I recommend using Amazon SES to send emails instead.
Amazon SES also requires an application for production access, but I think the hurdle is lower than lifting the restriction on port 25.
https://docs.aws.amazon.com/ses/latest/dg/request-production-access.html