How to Add External Promotions Using the HTML Block

If you manage promotions through an external platform — an ad server or campaign manager — you can still run them in your Letterhead newsletters. The HTML block embeds custom HTML code directly into a newsletter, which is ideal for third-party ad creatives and personalized snippets.

If you’d rather manage the ad inside Letterhead with scheduling and reporting, consider an HTML promotion instead. For everything the Promotions area can do, see Working in Promotions.

Insert an external promotion

1. In Emails, edit or create a newsletter.

2. Drag the HTML block from the block panel to where the promotion should appear.

3. Paste the HTML code you received from your external platform into the block.

4. Replace any placeholder merge tags with Letterhead’s personalization tags so variables resolve at send time:

   Placeholder	Replace with
   {EMAIL}	{{ email }}
   {FIRST_NAME}	{{ firstName }}
   {LAST_NAME}	{{ lastName }}

   See the complete list of personalization tags for everything available.

5. Turn on the Relax HTML Validation option so the code renders correctly.

Testing third-party ads

Test emails will not display third-party ads correctly. A test send isn’t recognized as a live send with a real subscriber, so the ad platform won’t populate the creative or count the impression. When you publish and send the real newsletter, the ad appears as expected.

Can I personalize these promotions?

Yes — include Letterhead merge tags in your HTML to insert subscriber info dynamically, as shown in the table above.