aws-lambda-mailer

An AWS Lambda function using nodemailer for serverless email sending.

Check Serverless Emails with AWS for a step-by-step guide on setting up a cloud-based email sending service.

Deployment

You can either manually upload a .zip file in your Lambda function, or use the deploy.sh script for automatic deployment:

./deploy.sh

In order to use the script you will need a .env file under the project's root. An example:

AWS_REGION=ap-southeast-2
AWS_FUNCTION_NAME=arn:aws:lambda:ap-southeast-2:999:function:sendEmail

⚠ If you follow the manual approach, you have to include both index.js and node_modules/nodemailer/* in the .zip file.

Usage

To invoke this function from a Node.js application, we must first add aws-sdk as a dependency:

npm install aws-sdk

An example implementation:

const Lambda = require('aws-sdk/clients/lambda');

const SEND_EMAIL_LAMBDA = 'myLambdaFunctionName'; // Your Lambda function name here

const lambda = new Lambda({
  accessKeyId: process.env.AWS_ACCESS_KEY_ID,
  secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
  region: process.env.AWS_REGION,
});

const sendEmail = (data, callback) => {
  const { from, to, subject, text, html } = data;
  const payload = { from, to, subject, text, html };

  return lambda.invoke(
    {
      FunctionName: SEND_EMAIL_LAMBDA,
      InvocationType: 'Event',
      Payload: JSON.stringify(payload),
    },
    /**
     * @function
     * @param {?Error} error
     * @param {?{ StatusCode, Payload }} results
     */
    (error, results) => callback(error, results),
  );
};

module.exports = sendEmail;

We also need to provide AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY and AWS_REGION in the execution environment.

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✍ Kostas Karvounis, 2019-2020