Val Davis

RDS Newsletter is a straightforward email newsletter plugin that does not overcomplicate things.
Features: 
* Import subscribers via CSV or plain text (one email per line) 
* Paste raw HTML as your email content 
* Optional templates (Basic and Modern included) 
* Batch sending with configurable limits (default 500 per hour) 
* Subscriber groups for targeted sends 
* Double opt-in with confirmation emails 
* Open and click tracking with reports 
* Automatic unsubscribe links in every email 
* Bounce detection with auto-delete via IMAP 
* IP address and timestamp logging for compliance 
* Signup and unsubscribe shortcodes 
* Send test emails before sending to your list 
* Schedule newsletters for later 
* Duplicate newsletters 
* Export subscribers as CSV
<h3>Shortcodes</h3>
Signup form: 
 [rdsnl_signup]
Optional attributes: 
* <code>title="Subscribe to our newsletter"</code> 
* <code>button_text="Subscribe"</code> 
* <code>group="3"</code> (group ID to auto-assign)
Unsubscribe form: 
 [rdsnl_unsubscribe]

RDS Newsletter

A self-hosted email newsletter plugin for WordPress with subscriber management, batch sending, open and click tracking, and bounce processing.

Inboxify

Inboxify is an online application for sending email newsletters. Many companies, mostly from the Netherlands, make use of Inboxify for sending newsletters to their customers and relations. At the moment, Inboxify is only available in Dutch.
With the Inboxify Sign Up Form plugin you can add sign up forms and checkboxes to your WordPress website to enable your visitors to sign up directly to your Inboxify list.
<h4>Features</h4>
<ul>
<li>Easy to use Sign Up Form Widget</li>
<li>Add a sign up form to your posts and pages using the shortcode [inboxify_subscribe]</li>
<li>Add a subscribe checkbox to your comment form, registration form or user profile form</li>
<li>Prevent spam submissions using one of the supported CAPTCHA plugins</li>
<li>Compatible with the “Really Simple CAPTCHA”, “SI CAPTCHA Anti-Spam” and “WordPress ReCaptcha Integration” plugins</li>
<li>AJAX form processing</li>
</ul>

Inboxify Sign Up Form

Easily add Inboxify newsletter sign up forms to your WordPress website with the offical Inboxify Sign Up Form plugin.

RDS Newsletter vs Inboxify Sign Up Form