How can I use HTML in Letterhead?

The HTML block lets you insert custom HTML directly into your newsletter. Built-in validation keeps your email compatible with email clients: problematic inputs — like script tags and HTML5 media objects — are automatically identified and restricted, so custom code can’t break your layout or deliverability.

Add an HTML block

1. From Emails, open a draft (blank or from a template).
2. Drag the HTML block from the block panel to where you want it.
3. Click the block placeholder — the HTML editor opens on the right.
4. Enter your markup. Changes save automatically.

Letterhead supported merge tags

You can use these merge tags inside your HTML:

• {{ campaignId }} — a unique identifier for the newsletter once published (empty before publication).
• {{ uniqueId }} — a unique identifier for the individual subscriber (empty before publication).
• {{ subscriber_email }} — the subscriber’s email address.
• {{ subscriber_name }} — the subscriber’s first name, if set in their profile.
• {{ subscriber_surname }} — the subscriber’s last name, if set in their profile.

For personalization elsewhere in your newsletter, see How do I personalize my newsletters? and audience profile fields.

Supported HTML elements and attributes

Element	Accepted attributes
<span>	—
<code>	—
<sub>, <sup>	id, class, style
<del>	id, class, title, style
<ins>	—
<small>	id, class, style
<font> (converts to <span>)	class, id, color, size, face, style
<a>	href, title, target, style
<em> / <i>	—
<strong> / <b>	—
<p>	id, class, style
<img />	class, id, src, alt, title, style, width, height
<table>	class, id, src, alt, title, style, width, height
<tr>	class, id, align, valign, style
<th>	class, id, colspan, rowspan, style, width, height
<td>	class, id, colspan, rowspan, valign, style, width, height
<h1>–<h4>	id, class, style
<br>	—
<ol>, <ul>, <li>	—
<dl>, <dt>, <dd>	id, class, style
<pre>	—
<link />	href, rel, type, media
<u> (converts to <span>)	—
<s> (converts to <span>)	—

For styling without code, see How do I use the new design settings? For advanced email-wide styling, see Custom CSS in emails.