CardeeTech.

Nerio J. Molina G.

PressPilot Email Template Customizer adds a presentation layer to outgoing WordPress emails. It does not replace <code>wp_mail()</code> and does not interfere with SMTP plugins.
Developed and maintained by CardeeTech (Cardee Technologies, SL).
Key features:
<ul>
<li>Wrap outgoing <code>wp_mail()</code> messages with a consistent HTML template.</li>
<li>Default Designer mode with visual tokens (logo, header image, colors, typography, width, radius).</li>
<li>Custom HTML mode with placeholder replacement.</li>
<li>Live preview in admin for faster iteration.</li>
<li>Built-in test email tool (single or multiple recipients).</li>
<li>WebP safety flow for email compatibility with PNG conversion cache.</li>
<li>Diagnostics panel for runtime checks and recent log visibility.</li>
</ul>
Template modes:
<ul>
<li>Default Designer: uses internal template + design tokens from settings.</li>
<li>Custom HTML: uses your HTML as-is and replaces supported placeholders.</li>
</ul>
Supported placeholders:
<pre><code>{{message}}, `{{subject}}`, `{{site_name}}`, `{{site_url}}`, `{{site_host}}`, `{{logo}}`, `{{header_image}}`, `{{date}}`, `{{year}}`, `{{preheader}}`
</code></pre>
Legacy compatibility during migration window:
<ul>
<li><code>{{ctetc_header_image}}</code> is still accepted for upgraded installations.</li>
</ul>

PressPilot Email Template Customizer

Wrap outgoing WordPress emails in a branded HTML template while keeping native wp_mail() delivery and SMTP compatibility.

rajuru

SparkPost

The <a href="https://www.sparkpost.com/" rel="nofollow ugc">SparkPost</a> email delivery service offers best in class deliverability to ensure your mail hits the inbox, live analytics to review, track and optimize your email activities, as well as highest performance when you need it most: always.
When the SparkPost plugin is enabled, all outgoing email from your WordPress installation is sent through your SparkPost service. From within <a href="https://app.sparkpost.com/" rel="nofollow ugc">the SparkPost UI</a> or <a href="https://app.eu.sparkpost.com/" rel="nofollow ugc">SparkPost EU UI</a>, you can then watch your campaigns unfold live by tracking your engagement metrics, learn what your audience responds to and even integrate more deeply with your app using the SparkPost API.
Requirements 
– PHP 7.0 or later 
– WordPress 5.5 or later

Send all your email from WordPress through SparkPost, the most advanced email delivery service.

PressPilot Email Template Customizer vs SparkPost