After moving their workload to AWS eu-central-1 region, an administrator would like to configure their email server on an Amazon EC2 instance in a private subnet of the VPC which will use Amazon SES. What is the most effective setup to implement?

Answer options:

A.Configure a VPC endpoint powered by AWS PrivateLink.
B.Ensure that the private subnet has a route to a NAT gateway in a public subnet.
C.Configure the email server with the appropriate Amazon SES endpoint for eu-central region, email-smtp.eu-central-1.amazonaws.com.
D.Configure the email server to use a service port other than port 25 to avoid Amazon EC2 throttling.

Correct Answer: A
As of April 29, 2020, AWS announced the addition of Amazon SES as a service available over VPC endpoint powered by AWS PrivateLink. This makes it possible to configure a VPC endpoint which the email server will reach within the VPC without the need for internet access. This is the most effective setup to implement.
https://aws.amazon.com/about-aws/whats-new/2020/04/amazon-ses-now-offers-vpc-endpoint-support-for-smtp-endpoints/
Option B is INCORRECT because ensuring that the private subnet has a route to a NAT gateway in a public subnet is feasible but would mean that the traffic would traverse the internet to get to the Amazon SES endpoints. This is not the most effective setup to implement.
Option C is INCORRECT because configuring the email server with the appropriate Amazon SES endpoint would not work since Amazon EC2 instance is in a private subnet and does not have internet access to reach it.
Option D is INCORRECT because configuring the email server to use a service port other than port 25 is recommended but does not address the requirement of how the email server will reach the Amazon SES endpoint.