Add SES Support to a Cognito User Pool in CDK

Integrating SES with Cognito User Pools in CDK #

Every time a user signs up for our application, or requests a password recovery, AWS Cognito sends them an email. By default Cognito sends emails from no-reply@verificationemail.com.

The default email configuration has many restrictions and quotas, for example - we can only send 50 emails per day and the subject of the email has to be less than 140 characters long.

Since the Level 2 UserPool construct doesn't expose a property for integrating with SES, we have to use an escape hatch to update the email configuration.

In order to configure SES for a Cognito User Pool in CDK, we have to get access to the CfnUserPool construct and update its emailConfiguration property.

const userPool = new cognito.UserPool(this, 'user-pool-id', {
  //...rest
});

// 👇 update Email sender for Cognito Emails
const cfnUserPool = userPool.node.defaultChild as cognito.CfnUserPool;
cfnUserPool.emailConfiguration = {
  emailSendingAccount: 'DEVELOPER',
  replyToEmailAddress: 'YOUR_EMAIL@example.com',
  sourceArn: `arn:aws:ses:YOUR_COGNITO_SES_REGION:${
    cdk.Stack.of(this).account
  }:identity/YOUR_FROM_EMAIL@example.com`,
};

Let's go over the properties we've set for email configuration:

• emailSendingAccount specifies whether Cognito should use the default email provider or our custom SES configuration. The DEVELOPER setting indicates that we'll provide our custom SES config.
• replyToEmailAddress specifies the email address users will be replying to
• sourceArn specifies the ARN of a verified email address. Note that cognito only integrates with SES in 3 regions: us-east-1, us-west-2, eu-west-1. The SES from-email has to be verified in the specific region, and your SES account must be out of the sandbox.

Further Reading #

• AWS CDK Tutorial for Beginners - Step-by-Step Guide
• How does AWS CDK work
• What is a Token in AWS CDK
• CDK Constructs - Complete Guide
• What is an identifier (id) in AWS CDK
• How to use Context in AWS CDK
• How to use Parameters in AWS CDK