Build a Blog Email Subscription Service using Zapier and Sendwithus

There are many different ways to get notified of new posts for you favourite blogs. For example, you could subscribe via RSS or follow a Twitter account (if there is one). There is also the good ol’ fashioned way – email subscriptions.

I wanted to add email subscription notifications to my blog (the thing you’re reading) but didn’t want it to be a manual process email every time I published something new. So, I thought a little bit and realized I could combine a couple services (Zapier and Sendwithus) to come up with something automated. This post is going to outline the steps needed to build an email notification system without writing a single line of code.

I should point out that I am a developer at Sendwithus, but it really doesn’t matter. These instructions can be modified to work with almost any email tool.

The Requirements

What does our email subscription service need to do? This is what I asked myself before starting. Well, there are just a few basic requirements.

  • should be able to send an email to a list of subscribers
  • should send the emails automatically when a new post goes live
  • email content should be dynamically generated based on the new blog post

Each one of these requirements is non-trivial. Building something from scratch to satisfy these would take a lot of time and on require ongoing maintenance. Let’s not waist our time. That’s where our tools come in.

Introducing the Tools

Now that we know what our email service needs to do, how do we build it? There are two tools that work espicially well together that we’re going to use to solve this problem: Zapier and Sendwithus.


Zapier is a service that makes it really easy to link together different web services. The main feature Zapier is the ability create what they call a Zap. A Zap consists of two parts. A source event and an action. Once the Zap is created, whenever Zapier sees the source event happen it will trigger the action. This is a pretty hand-wavy explanation so I put together some examples to help you understand.

  • when I post a new tweet, text that tweet to my mom using Twilio
  • when a new issue is created in Github, also create a task in Trello
  • when a phone number recieves an SMS (Twilio), unlock my door using Lockitron

You get the picture. You can pretty much do anything you want, including…

  • when an RSS feed updates, send an email to my blog subscribers using Sendwithus

Amazing right? That’s exactly what we want!

Now that we know a bit about Zapier, lets talk a bit about Sendwithus.


Sendwithus, to put is simply, is a hosted API platform for sending templated email. What does this mean? It means that you can programmatically send highly dynamic and personalized email using any programming language you want.

Here are the core Sendwithus features we’ll be using:

  • premade responsive email starter templates
  • HTML email templating with Jinja2
  • sending email to a customer segment

These three things combined are all we need to get this working. Now that we’ve introduced the tech we’ll be using, let’s get started on the real work.

Step 1 – Create a Zap

We’re going to skip the easy stuff like registering accounts for Sendwithus and Zapier. I trust you’re smart enough to figure those out on you’re own. So, we’ll just dive right in and create our first Zap.

On the “Make a New Zap” page, there are two dropdowns. We’re going to select our event source (RSS) from the first one, and our action (Sendwithus) in the second. If you haven’t yet connected your Sendwithus account to Zapier, Zapier will prompt you to put in your API key, but that’s all you need to get going.

After selecting Sendwithus, choose the “Send to Segment” action from the dropdown as the picture below shows. A segment in Sendwithus is basically a dynamic customer list, defined by one or many rules. The rule that defines my blog subscribes segment is have property "confirmed" equals "YES". This tutorial won’t be showing you how to get customers into Sendwithus but, if you’re interested, let me know on Twitter and I’ll consider that for a future post.

Step 2, 3 – Connect a Sendwithus Account

This step is where we configure our accounts. We simply select the Sendwithus account that we connected to Zapier and leave the RSS account alone (RSS doesn’t have accounts).

After selecting your Sendwithus account, Zapier will make an authentication call to ensure that everything is configured correctly.

Step 4 – Select an RSS Feed

This is where the we start seeing the magic. Zapier’s RSS integration is pretty advanced but, for our purposes, we’ll only be using the basic settings. Simply copy and paste the URL of your RSS feed into the first input box and we’re done.

If you want to get really advanced, you can do cool stuff like only trigger this Zap when the new RSS item matches a specific filter (COOL!).

Step 4 – Configure the Action

The next thing we need to do is set up our Sendwithus action. At this point, I have already created a new email template inside Sendwithus. All I did was modify one of the stock templates to change some colors and add some templating. We’ll get to that in a second.

So, to configure the action, we need to set a few things. The first one is the email template that we want to send. So, select the one that you’ve created from the dropdown. Next, we need to select the customer segment that we want to send to. This is the segment that I mentioned earlier (remember?).

Now that we’ve done that, we need to define the dynamic data that will be passed to Sendwithus to render the email. The image below shows the three variables we’ll be pulling out of the RSS feed item (url, title, description).

What is this doing exactly? Once the Zap is live, Zapier will start watching the RSS feed. Once Zapier detects that a new item has been added, it will pull the variables we want out of the feed item. Once Zapier has these, it will pass the data to Sendwithus in an API call. Once Sendwithus receives this API call, it will render the email template with the given data, and deliver it to the customer segment.

We can reference the given variables from within our Sendwithus template using the Jinja2 template language. Here’s an example of an extremely basic email template.

{% raw %}

        <!-- Title of the RSS feed item -->
        <h1>{{ title }}</h1>

        <!-- First 130 characters of the RSS feed content -->
        <p>{{ description | truncate(130, end="...") }}</p>

        <!-- A link to read the post -->
        <a href="{{ url }}">Click Here to Read</a>

{% endraw %}

While this is an extremely basic example, making a friendly and colorful email is not much more work. Sendwithus provides a bunch of responsive email templates that you can modify for your needs. I modified a template from the Neopolitan theme in less than ten minutes.

Here’s what my template looks like in the Sendwithus app.

Step 5 – Test the Zap

Alright, now that we have everything set up, how do we know it works? Fortunately, Zapier lets you test a Zap by pulling in data from the last RSS feed items and giving you an option to trigger them manually. This is awesome because you get to test your Zap with real content!

Since we don’t want to send a test email to our whole subscriber list, first make a test segment in Sendwithus that only contains a test email address. Use the email address contains "" rule to accomplish this. Once you’ve safely tested the Zap, switch it back to the real segment.

After my own testing, this is what the email looked like in my inbox (pun intended).

Wrap Up

That’s it! We have built fully automated email service in about an hour with no programming required, thanks to Zapier and Sendwithus :)

Oh, and I should also mention that these services are totally free for low-volume use cases like this one.

As always, let me know if you have any questions or comments. Thanks for reading!

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