Configure Email Server on Amazon EC2 in Private Subnet using Amazon SES

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.

When an administrator wants to configure an email server on an Amazon EC2 instance in a private subnet of a VPC, there are several considerations to keep in mind.

Option A: Configure a VPC endpoint powered by AWS PrivateLink This option involves creating a VPC endpoint powered by AWS PrivateLink, which allows the email server in the private subnet to communicate with Amazon SES without the need for an internet gateway or NAT gateway. Instead, the traffic flows over the Amazon network, which can provide improved security and reliability. This can be an effective option for organizations that require a high level of security for their email communications.

Option B: Ensure that the private subnet has a route to a NAT gateway in a public subnet This option involves creating a NAT gateway in a public subnet and ensuring that the private subnet has a route to that gateway. This allows the email server in the private subnet to communicate with Amazon SES via the internet, using the NAT gateway as a proxy. This option can be effective for organizations that do not require the highest level of security for their email communications but still want to ensure that their traffic is encrypted and travels over a reliable connection.

Option C: Configure the email server with the appropriate Amazon SES endpoint for the eu-central region, email-smtp.eu-central-1.amazonaws.com This option involves configuring the email server with the appropriate Amazon SES endpoint for the eu-central region. This endpoint allows the email server to communicate directly with Amazon SES over the internet. This option can be effective for organizations that do not require a high level of security for their email communications and want a simple setup.

Option D: Configure the email server to use a service port other than port 25 to avoid Amazon EC2 throttling This option involves configuring the email server to use a service port other than port 25 to avoid Amazon EC2 throttling. This can be effective for organizations that send a large volume of email from their EC2 instances and want to avoid being throttled by Amazon. However, it may not be necessary for all organizations, and it does not address security concerns.

In summary, the most effective setup to implement will depend on the organization's specific needs and requirements. Option A is the most secure and reliable option, but it may not be necessary for all organizations. Option B provides a good balance between security and simplicity. Option C is the simplest option, but it may not be sufficient for organizations with high-security requirements. Option D can be effective for organizations that send a large volume of email but does not address security concerns.