Add newsletter ad revenue to HubSpot marketing emails
HubSpot Marketing Hub supports custom HTML modules in email templates. Integrate MailAdx via a personalized token for the subscriber email hash and an open-time ad image URL.
Why add MailAdx to HubSpot?
How to integrate MailAdx with HubSpot
- 1
Create your MailAdx publisher account
Sign up and configure ad placements with floor CPMs in the Publisher Portal.
- 2
Create a custom coded email template module in HubSpot
In HubSpot's email editor, add a custom HTML module. HubSpot uses HubL personalization tokens for contact properties.
- 3
Set up the email hash contact property
Create a custom contact property for the SHA-256 email hash. Populate it via HubSpot workflows or API when contacts are created or updated.
- 4
Paste the MailAdx ad tag with the HubL token
Reference your custom property in the ad tag URL (e.g., {{ contact.email_hash }}). Paste the complete tag into your HTML module.
- 5
Test and go live
Send a test email, verify the ad loads on open, and activate for production sends.
HubSpot editor tips
HubSpot requires a coded email template or a custom HTML module in a drag-and-drop template. Marketing Hub Professional+ supports HubL tokens. Add the module to your master template so all campaigns inherit the placement.
<!-- 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 -->HubSpot + MailAdx: common questions
Does MailAdx work with HubSpot workflows?
Yes. Any HubSpot marketing email template can include the MailAdx ad tag. Automated workflow emails trigger the same open-time ad decision as manual campaigns.
What HubSpot plan do I need?
You need Marketing Hub with email sending and the ability to add custom HTML modules. Most Professional and Enterprise plans support this.
How does billing work when I send through HubSpot?
You pay HubSpot for email delivery as usual. MailAdx charges only when a subscriber opens and the ad image is requested — not when HubSpot sends the email. A 10,000-recipient send with a 35% open rate generates roughly 3,500 billable impressions, not 10,000.
Can I use multiple ad placements in one HubSpot template?
Yes. Create separate ad units in MailAdx (e.g., header, mid-roll, footer) and paste each tag in a different HTML block. Each placement has its own floor CPM and reporting in the Publisher Portal.
Does the HubSpot integration work on mobile email clients?
Yes. MailAdx serves standard HTML image tags that render in Gmail iOS/Android, Apple Mail, Yahoo, and Outlook mobile. No JavaScript runs inside the inbox — the ad is a plain image request at open time.
Billing with HubSpot
MailAdx bills publishers a flat platform fee per impression served — typically $0.30–$0.50 CPM — regardless of which ESP you use. Your HubSpot subscription fee is separate; MailAdx does not charge per send or per subscriber. Advertisers pay you directly (or via programmatic demand) above the platform fee. Top up credits in the Publisher Portal before going live; impressions pause gracefully when credits reach zero.
Troubleshooting HubSpot + MailAdx
Ad image shows as broken or blank
Confirm the email-hash merge field substitutes in a real HubSpot test send — not just the editor preview. An empty hash causes MailAdx to skip the auction. Re-send a test to yourself, view the raw HTML source, and verify the eh= parameter is populated.
Impressions not appearing in Publisher Portal
Open the test email in a client that loads remote images (Gmail web, Apple Mail with images enabled). Some corporate Outlook configs block external images by default. Wait 60 seconds and refresh the portal — reporting is near-real-time.
Merge field syntax error in template
Each ESP uses different personalization syntax. Double-check you replaced {{EMAIL_SHA256}} in the MailAdx tag with HubSpot's exact variable from the setup steps above. A typo in the merge tag will break the URL at open time.
Related resources
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