AppRunner and SES

Connection timed out means application is unable to establish connection to the AWS SES service. This could be possible due to the incorrect network configuration. Please note that when working with AWS App Runner it is required to send outbound communication via a NAT Gateway. As mentioned within the following AWS documentations [1][2], when connected to a VPC, all outbound traffic from your AppRunner service will be routed based on the VPC routing rules. Services will not have access to the public internet unless allowed by a route to a NAT Gateway.

Therefore, It is suggested to confirm if the App runner service is deployed in a Private Subnets and also please ensure that your private subnets have route to internet via NAT gateway.

References :

[1] Enabling VPC access for outgoing traffic - https://docs.aws.amazon.com/apprunner/latest/dg/network-vpc.html

[2] https://aws.amazon.com/blogs/aws/new-for-app-runner-vpc-support/

Hi, @Michael4824

You probably have App Runner's network mode set to VPC.

In that case, outbound other than HTTP responses from the container go through the custom VPC.
If the subnet your App Runner is assigned to does not have an outbound route to an SMTP server, it will time out.

You need to create a route to your NAT gateway in your subnet or a VPC endpoint for SES (SMTP).