Email Append

This tutorial will show you how to use our Email Append feature with your existing newsletters to identify more customers and how to implement this with other email solutions.

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Our Email Append feature enables you to leverage your existing newsletter sends with Rejoiner to identify more customers. This feature uses click-through data from your other email marketing efforts, like Mailchimp, in order to track and identify more customers via their email address.

To identify and target your subscribers you will need to append a query string on any link you're directing customers. Note that these links MUST redirect your subscribers back to your store in order for the Email Append feature to work. If you are redirecting subscribers to links that are not directly associated with the domain on your Rejoiner account, we will not be able to identify them at all. 

See email append in action here.


Appending Structure

The query string you'll need to create in your non-Rejoiner campaign has the following structure:

The URL of the page you're redirecting subscribers to
A question mark to signal the start of your query string ?
Any variable name you'd like to use to define a subscriber's email with an equal sign at the end email=
The email address of your customer

These would all need to be added inside the href portion of your links' HTML code to create something like this:

<a href="" target="_blank"/>Some Link Text</a>

Rejoiner would then see the ‘email’ variable (as per the example above) and identify the subscriber. 

But how do you inject the email of a subscriber?

That depends on the service you use to send your newsletters. Below you will see a tutorial for implementing Email Append with Mailchimp. If you need instructions for a different email service, please email

Mailchimp Implementation

Simply follow the steps below to implement Email Append into your Mailchimp's newsletters:

Log into your  Mailchimp account.
Go into the campaign you want to implement our email append feature.
Go into the edit mode of the campaign. We recommend you watch the video below, which will guide you through steps 4 to 8:
We will be editing the HTML of your campaign.

First, inside the href section of your link(s), you’ll want to start by adding the url of the page you’re directing your leads to.

<a href="" target="_blank">Redeem your offer here</a>
Note: The domain of this URL must be the same as the domain of your Rejoiner account.
Next, structure your query string starting with the email variable name you'll use

Variable Name Example:


Add your subscriber's email using  Mailchimp's merge tags. Below is the tag you'll need to use:


The final result will look something like this:

<a href="*|EMAIL|*">Redeem your offer</a>

If you store customer Rejoiner ID in MailChimp, this is preferable to email. To use Rejoiner ID, you'll need to identify your list's merge tag used to store the Rejoiner ID. For example, if your Rejoiner ID merge tag is named RJID in your list, the tag you'll need to use would be:


Then the final result will look something like this:

<a href="*|RJID|*">Redeem your offer</a>
Save your changes.
Verify Your Mailchimp Implementation

To test that that your Mailchimp implementation will be successful, we need to test for two things:

  • We need to verify that Mailchimp is injecting a subscriber's email in your link's query string. We could do this via a live test, or via the "Enable live merge tag info" feature inside Mailchimp's campaign editor.
  • We also need to make sure that we're capturing the email address of your subscribers in order to remarket to them. 

To help you, we created the video below, which will show you how to test both cases.


Constant Contact Implementation

Simply follow the steps below to implement Email Append into your Constant Contact's newsletters:


We HIGHLY recommend you watch the video tutorial below.

Log into your  Constant Contact Account
Go into the campaign you want to implement our email append feature.
Verify that the campaign is connected to a list. If you have no list attached, Constant Contact will not inject any subscriber data into our test send.
Note: We also recommend that you start with a dummy campaign and a Test List for your first iteration of testing. This will help you avoid sending something you're not ready to send to all your subscribers.


Please watch the video below:

Need instructions for another email service? Send your request to

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