Check the nodemailer version

Oct 13, 2025 by magicalceylontours.com 120 views

Introduction

As a developer, you may have encountered situations where you need to configure your email server to work with a specific environment, such as a Kubernetes cluster. In this case, you may have an SMTP server that serves STARTTLS on port 587, but the bound certificate is only valid for production hosts, not inner cluster hosts. This can lead to issues when trying to send emails from within the cluster. In this article, we will explore how to allow disabling of tls.rejectUnauthorized independently of NODE_ENV using nodemailer.

Problem Statement

By default, nodemailer's tls.rejectUnauthorized option is set to true when NODE_ENV is not set to development. This means that if you are running your application in a production environment, nodemailer will reject any unauthorized TLS connections, which can lead to issues when trying to send emails from within a Kubernetes cluster.

Use Case: SMTP Server within a Kubernetes Cluster

Let's say you have an SMTP server running within a Kubernetes cluster, and it serves STARTTLS on port 587. The bound certificate is only valid for production hosts, not inner cluster hosts. In this case, you may want to configure nodemailer to disable tls.rejectUnauthorized independently of NODE_ENV.

Current Workaround: `EMAIL_SERVER_SKIP_TLS_CHECK`

Currently, you can configure nodemailer to disable tls.rejectUnauthorized by setting the EMAIL_SERVER_SKIP_TLS_CHECK environment variable to true. However, this requires you to set NODE_ENV to production as well, which may not be desirable in all cases.

Proposed Solution: Allow Disabling of `tls.rejectUnauthorized` Independently of `NODE_ENV`

To address this issue, we propose allowing disabling of tls.rejectUnauthorized independently of NODE_ENV. This can be achieved by introducing a new option, tls.rejectUnauthorized, which can be set to false regardless of the NODE_ENV value.

Implementation

To implement this feature, we can modify the nodemailer code to introduce a new option, tls.rejectUnauthorized. We can then use this option to determine whether to reject unauthorized TLS connections or not.

// nodemailer.js
const tls = require('tls');

module.exports = {
  // ...
  tls: {
    rejectUnauthorized: false, // default value
  },
  // ...
};

Usage

To use this feature, you can simply set the tls.rejectUnauthorized option to false when creating a nodemailer transport:

const nodemailer = require('nodemailer');
const transport = nodemailer.createTransport({
  host: 'smtp.example.com',
  port: 587,
  tls: {
    rejectUnauthorized: false,
  },
});

Benefits

Allowing disabling of tls.rejectUnauthorized independently of NODE_ENV provides several benefits:

Flexibility: You can now configure nodemailer to disable tls.rejectUnauthorized regardless of the NODE_ENV value.
Improved security: By disabling tls.rejectUnauthorized, you can ensure that your application can send emails from within a Kubernetes cluster without encountering issues.
Simplified configuration: You no longer need to set NODE_ENV to production to disable tls.rejectUnauthorized.

Conclusion

In conclusion, allowing disabling of tls.rejectUnauthorized independently of NODE_ENV provides a flexible and secure solution for configuring nodemailer in various environments. By introducing a new option, tls.rejectUnauthorized, we can simplify the configuration process and improve the overall security of our applications.

Future Work

In the future, we can consider introducing additional options to further customize the behavior of nodemailer. For example, we can introduce an option to specify a custom certificate or key for TLS connections.

Example Use Cases

Here are some example use cases for this feature:

Kubernetes cluster: You can use this feature to configure nodemailer to disable tls.rejectUnauthorized when running your application in a Kubernetes cluster.
Development environment: You can use this feature to configure nodemailer to disable tls.rejectUnauthorized in your development environment, making it easier to test and debug your application.
Production environment: You can use this feature to configure nodemailer to disable tls.rejectUnauthorized in your production environment, ensuring that your application can send emails without encountering issues.

Commit Message

Here is an example commit message for this feature:

feat: allow disabling of tls.rejectUnauthorized independently of NODE_ENV

API Documentation

Here is an example API documentation for this feature:

tls.rejectUnauthorized: A boolean option that determines whether to reject unauthorized TLS connections or not. Default value is false.

Troubleshooting

If you encounter any issues with this feature, you can try the following troubleshooting steps:

Check the nodemailer version: Ensure that you are using the latest version of nodemailer.
Check the configuration: Verify that the tls.rejectUnauthorized option is set to false in your nodemailer configuration.
Check the TLS certificate: Ensure that the TLS certificate is valid and properly configured.

Introduction

In our previous article, we explored how to allow disabling of tls.rejectUnauthorized independently of NODE_ENV using nodemailer. In this article, we will answer some frequently asked questions (FAQs) related to this feature.

Q: What is the purpose of `tls.rejectUnauthorized` in nodemailer?

A: The tls.rejectUnauthorized option in nodemailer determines whether to reject unauthorized TLS connections or not. By default, it is set to true when NODE_ENV is not set to development. This means that if you are running your application in a production environment, nodemailer will reject any unauthorized TLS connections.

Q: Why is it necessary to disable `tls.rejectUnauthorized` in some environments?

A: Disabling tls.rejectUnauthorized is necessary in some environments, such as Kubernetes clusters, where the bound certificate is only valid for production hosts, not inner cluster hosts. In such cases, nodemailer will reject any unauthorized TLS connections, leading to issues when trying to send emails from within the cluster.

Q: How can I disable `tls.rejectUnauthorized` independently of `NODE_ENV`?

A: To disable tls.rejectUnauthorized independently of NODE_ENV, you can set the tls.rejectUnauthorized option to false in your nodemailer configuration. This will allow nodemailer to send emails without rejecting unauthorized TLS connections.

Q: What are the benefits of disabling `tls.rejectUnauthorized` independently of `NODE_ENV`?

A: Disabling tls.rejectUnauthorized independently of NODE_ENV provides several benefits, including:

Flexibility: You can now configure nodemailer to disable tls.rejectUnauthorized regardless of the NODE_ENV value.
Improved security: By disabling tls.rejectUnauthorized, you can ensure that your application can send emails from within a Kubernetes cluster without encountering issues.
Simplified configuration: You no longer need to set NODE_ENV to production to disable tls.rejectUnauthorized.

Q: How can I configure nodemailer to disable `tls.rejectUnauthorized`?

A: To configure nodemailer to disable tls.rejectUnauthorized, you can use the following code:

const nodemailer = require('nodemailer');
const transport = nodemailer.createTransport({
  host: 'smtp.example.com',
  port: 587,
  tls: {
    rejectUnauthorized: false,
  },
});

Q: What are some example use cases for disabling `tls.rejectUnauthorized` independently of `NODE_ENV`?

A: Some example use cases for disabling tls.rejectUnauthorized independently of NODE_ENV include:

Kubernetes cluster: You can use this feature to configure nodemailer to disable tls.rejectUnauthorized when running your application in a Kubernetes cluster.
Development environment: You can use this feature to configure nodemailer to disable tls.rejectUnauthorized in your development environment, making it easier to test and debug your application.
Production environment: You can use this feature to configure nodemailer to disable tls.rejectUnauthorized in your production environment, ensuring that your application can send emails without encountering issues.

Q: What are some common issues that may arise when disabling `tls.rejectUnauthorized` independently of `NODE_ENV`?

A: Some common issues that may arise when disabling tls.rejectUnauthorized independently of NODE_ENV include:

TLS certificate issues: Ensure that the TLS certificate is valid and properly configured.
Nodemailer version issues: Ensure that you are using the latest version of nodemailer.
Configuration issues: Verify that the tls.rejectUnauthorized option is set to false in your nodemailer configuration.

Q: How can I troubleshoot issues related to disabling `tls.rejectUnauthorized` independently of `NODE_ENV`?

A: To troubleshoot issues related to disabling tls.rejectUnauthorized independently of NODE_ENV, you can try the following steps:

Check the nodemailer version: Ensure that you are using the latest version of nodemailer.
Check the configuration: Verify that the tls.rejectUnauthorized option is set to false in your nodemailer configuration.
Check the TLS certificate: Ensure that the TLS certificate is valid and properly configured.

By following these steps, you should be able to troubleshoot and resolve any issues related to disabling tls.rejectUnauthorized independently of NODE_ENV.