As with so many things in AWS, it's left up to the customer to inform AWS that a) you're running a mail server, b) what the purpose/use case is and c) request they configure the reverse lookup associated with the elastic IP you've allocated.
Source: I've been running public facing SMTP servers in EC2 for years with no issues.
As with so many things in AWS, it's left up to the customer to inform AWS that a) you're running a mail server, b) what the purpose/use case is and c) request they configure the reverse lookup associated with the elastic IP you've allocated.
Source: I've been running public facing SMTP servers in EC2 for years with no issues.