🐒ESP Integration

Add programmatic and direct ad revenue to your Mailchimp newsletter

MailAdx integrates with Mailchimp via a standard HTML content block and the *|EMAIL_SHA256|* merge tag. Monetize your Mailchimp audience with open-time ads — no webhooks required.

Why add MailAdx to Mailchimp?

Open-time ad serving — impressions count only on genuine opens
No revenue share — flat per-impression fee, you keep the rest
Direct-sold + programmatic demand in a single waterfall
Custom price floors per ad placement
Real-time delivery dashboard and per-send reporting
Native ads (composite PNG) and standard banner formats

How to integrate MailAdx with Mailchimp

  1. 1

    Create your MailAdx publisher account

    Sign up at mailadx.com/signup and get approved (up to 24 hours). No credit card required.

  2. 2

    Create an ad placement and copy the ad tag

    In the Publisher Portal, create a new Ad Unit. Set your floor CPM and format. Copy the generated HTML ad tag.

  3. 3

    Ensure the EMAIL_SHA256 merge tag is available

    Mailchimp provides *|EMAIL_SHA256|* as a built-in merge tag — no setup required. This substitutes each subscriber's hashed email when the send is processed.

  4. 4

    Add an HTML content block to your Mailchimp template

    In the Mailchimp email editor, drag a Code block (or Custom HTML block) into your template where you want the ad. Paste the MailAdx ad tag, replacing {{EMAIL_SHA256}} with *|EMAIL_SHA256|*.

  5. 5

    Preview and test

    Use Mailchimp's preview with a real subscriber record to confirm the merge tag substitutes correctly. Send a test to yourself, open the email, and verify the ad loads in your Publisher Portal.

email-template.html
<!-- MailAdx ad tag — decision runs at open time -->
<a href="https://mailadx.com/api/v1/serving/click?pub=YOUR_PUB&pk=header&eh={{EMAIL_SHA256}}"
   target="_blank">
  <img src="https://mailadx.com/api/v1/serving/display?pub=YOUR_PUB&pk=header&eh={{EMAIL_SHA256}}&w=600&h=100"
       width="600" height="100" alt="" />
</a>
<!-- Replace {{EMAIL_SHA256}} with your ESP's email hash merge tag -->

Mailchimp + MailAdx: common questions

Does MailAdx replace Mailchimp Ads?

MailAdx is a replacement for Mailchimp's passive ad network for publishers who want more control. You own the advertiser relationship, set your own floors, and access programmatic demand beyond Mailchimp's marketplace.

Which Mailchimp plans support HTML blocks?

Custom HTML blocks are available on Mailchimp's Essentials, Standard, and Premium plans. The free plan has limited template customization — check your plan's template editor for the Code block option.

Ready to monetize your Mailchimp newsletter?

Free to start. No revenue share. Direct advertiser relationships from day one.

No credit card required
Setup in 30 minutes
Dedicated onboarding