cubefeed

The problem: SMTP email delivery by some hosting providers can be extremely slow. This plugin reconfigures the wp_mail() function to send email using HTTPS (via Elasticemail API) instead of SMTP and creates an options page that allows you to specify various options.
Plugin Settings Options:
<ul>
<li>Enable or Disable Plugin.</li>
<li>Elasticemail API username</li>
<li>Elasticemail assigned API Key</li>
<li>Elasticemail REST API URL</li>
<li>Your account channel variable(optional)</li>
</ul>

ElasticEmail Plugin

Reconfigures the wp_mail() function to send email using HTTPS (via Elasticemail) instead of SMTP and creates an options page to manage the settings.

EverPress

Xaver

Mailster Newsletter Plugin

This add on helps to integrate the <a href="https://mailster.co/?utm_campaign=wporg&utm_source=wordpress.org&utm_medium=readme&utm_term=WPML" rel="nofollow ugc">Mailster Newsletter Plugin for WordPress</a> with WPML. Requires at least version 2.3 of the Mailster Plugin.
Please follow the setup guide on our <a href="https://kb.mailster.co/using-multi-language-newsletter-with-wpml/?utm_campaign=wporg&utm_source=WPML&utm_medium=readme" rel="nofollow ugc">knowledge base</a>
<blockquote>
This Plugin requires <a href="https://mailster.co/?utm_campaign=wporg&utm_source=wordpress.org&utm_medium=readme&utm_term=WPML" rel="nofollow ugc">Mailster Newsletter Plugin for WordPress</a>
</blockquote>
<h3>Additional Info</h3>
This Plugin requires <a href="https://mailster.co/?utm_campaign=wporg&utm_source=wordpress.org&utm_medium=readme&utm_term=WPML" rel="nofollow ugc">Mailster</a>.

Mailster WPML

This add on helps to integrate the Mailster Newsletter Plugin for WordPress with WPML. Requires at least version 2.3 of the Mailster Plugin.

ElasticEmail Plugin vs Mailster WPML