Sending emails from Heroku Apps

Sending emails from Heroku Apps

Almost any modern application has the function of sending emails. You can send personalized email notifications to your customers, as well as send out marketing or newsletter emails. In this case, you need a tool that makes it easy and simple.

The IronMQ Heroku add-on allows you to add emails to the message queue and send them in parallel. This is a critical function if you have a large customer database. Try the demo version of IronMQ to send emails today.


This article will dive into how to use IronMQ Heroku Add-on to send emails from your Heroku apps.

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Table of Contents


What do You Need to do to Send an Email From a Heroku App?

Heroku overview

Heroku is a platform as a service that allows you to build, deploy, run, and manage applications in the cloud. It has a lot of tools for developing and managing the application that greatly simplifies the work of programmers. Heroku ensures the security of your data and prevents any potential security issues. It also has services for storing data and managing and monitoring the application in real-time. 

Heroku allows you to easily create and deploy new software releases. It can automatically detect bursts of traffic and create multiple new instances of an application to process requests. Heroku contains tools for organizing collaboration between users and can be used to manage, configure resources, change permissions, and more. It allows you to focus on developing the core functionality of your application without being distracted by repetitive tasks.

One of the tasks that most modern applications regularly perform is sending emails. You can easily solve this task using Heroku and several of its add-ons. 

Creating and sending emails

The process of creating and sending emails can be broken down into several steps. 

  1. Preparing headings. At this stage, you need to specify the sender, subject, and other general information.
  2. Creating and sending emails. Use IronMQ add-on to perform background tasks such as creating emails. In order to send emails to your clients, you need to use an SMTP gateway, for example, SendGrid. Heroku has a Twilio SendGrid add-on that you can easily integrate into your application.
  3. Processing of the received result. This step could include the following actions: notifying the application if an error occurred while sending the email, resending the email if it was not delivered, writing the result in the log.

Parallel email sending

It is a very common need to send emails to multiple users at the same time. If you have a large customer database, this process can take a long time. In practice, it is often necessary to send emails at a specific time, so emails should be sent to all users at the same time. This can be easily done using IronMQ.

To send emails from the Heroku app, you need to install the IronMQ add-on and the add-on for actually sending emails through SMTP like Twilio SendGrid.

To ensure that your emails are delivered to their recipients accurately, use the Heroku IronMQ add-on. We will go into more detail on how to use IronMQ to send emails below.

Add-ons Overview


Heroku add-ons are tools that provide additional functionality to your applications. You can easily install them into your application, choose the plan that suits you and take advantage of all the features they offer to simplify and speed up the development process.


All add-ons in Heroku are divided into several categories, depending on the functionality they perform. Using Heroku add-ons, you can save data to a database, manage databases, find and fix errors, monitor your application, process data, and much more. You can find a complete list of add-on categories here.

Using add-ons

  1. You can install any number of add-ons in your application.
  2. You can install more than one instance of the same add-on service in one application.
  3. It is possible to share add-ons between several applications that have a common owner.
  4. Some add-ons have dashboards that you can use to customize the add-ons.

Interaction of add-ons with the application

Add-ons can:

  1. Write and read application logs.
  2. View information about the application and about its owner.
  3. Add and modify configuration variables.
  4. Listen to deploy events.
  5. Listen to domain add or remove events. Serverless Tools

Speak to us to learn how IronWorker and IronMQ are essential products for your application to become cloud elastic.

Using IronMQ Heroku add-ons for Sending Emails

With IronMQ, you can easily implement emails that will retry sending. Emails can be placed in a message queue that uses some kind of identifier, such as user IDs. Workers can be periodically launched in order to take an email from the queue and send it. IronMQ saves messages in the queue until they are removed. Messages are not removed from the queue until the worker sends them. If an error occurred while sending an email or a worker crashed, the message will be returned to the queue for retrying automatically, without any of your actions.

Configure IronMQ

In order to configure IronMQ for your Heroku application, you only need to follow a few simple steps. Let’s take a look at how to do this using the Heroku dashboard or command line.

Using the Heroku dashboard to configure IronMQ

  1. Go to the IronMQ Add-on page.
  2. Find and click the Install IronMQ Message Queue button in the top right corner.
  3. Follow the installation instructions that appear on the screen.

Using the command line to configure IronMQ

  1. Install the IronMQ add-on for Heroku using the following command:
$ heroku addons:create iron_mq:developer
  1. Сhoose the programming language you are using and install the appropriate IronMQ client library.
$ gem install iron_mq
  1. Get Token and Project ID.
$ heroku config | grep IRON
  1. Use the installed client library to interact with IronQM API. 

IronMQ Benefits

  1. Access to the functions of creating and managing the message queue through a simple and straightforward REST API interface.
  2. The ability to use IronMQ for developing in almost any modern programming language, including Ruby, Python, PHP, Java, Go, Node.js.
  3. The ability to monitor message queues in real-time. You can see the number of items in the queue, the speed of processing items, and other statistics. This allows you to analyze your application work, find and fix errors quickly and easily.
  4. Stores data securely until it is delivered to the recipient. Even if an error occurs, the data will be re-sent.
  5. IronMQ message queue stores data in a background thread. This means that users can complete their request immediately, even if the message is not received for a while.
  6. To increase efficiency, it allows you to process data in batches.
  7. Asynchronous messaging capability. Messages and responses can occur not simultaneously.
  8. Support for push and pull queues.
  9. IronMQ supports long polling. This means IronMQ will wait for a message to be available to send a response. This eliminates empty responses.
  10. Supports error queues, message notifications, message triggers.
  11. IronMQ operates across multiple clouds and availability zones. This allows users to use alternate zones in case of failure.
  12. IronMQ has a robust data warehouse to ensure the reliability of your data.
  13. IronMQ uses the best cloud infrastructure to ensure the high availability of data.
  14. Supports messages up to 256 KB. IronMQ allows transferring larger messages using the 1 MB IronCache.
  15. IronMQ uses HTTPS encryption for its API and requires authorization, which uses the OAuth2 authentication protocol. Thus, IronMQ ensures the security of the transmitted data.
  16. The ability to manage the load on the system without the need to manage the infrastructure.
  17. High scalability.
Sending emails from Heroku Apps


Are you still in doubt about how to organize the creation and sending of emails in your application? How do you make sure all emails are sent to users at a specific time, even if you have a huge customer database? Use the IronMQ addon for Heroku to help make your email sending process fast and reliable.


IronMQ allows you to resubmit emails when an error occurs, as well as create parallel processes for sending emails. Try the IronMQ demo for free and make sure that this is the best solution for your application.

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