Allowing your visitors to subscribe to your newsletter should be easy. With this plugin, it finally is.

This plugin helps you grow your mailflatrate lists and write better newsletters through various methods. You can create good looking opt-in forms or integrate with any existing form on your site.

Some features

  • Connect with your mailflatrate account in seconds.

  • Sign-up forms which are good looking, user-friendly. You have complete control over the form fields and can send anything you like to Maiflatrate account.

What is mailflatrate?

mailflatrate is a newsletter service that allows you to send out email campaigns to a list of email subscribers. It is free for lists up to 2000 subscribers, which is why it is the newsletter-service of choice for thousands of businesses.

This plugin allows you to tightly integrate your WordPress site with your Mailflatrate account.

If you are not yet using mailflatrate, creating an account is 100% free and only takes you about 30 seconds.


you can also contact mailflatrate support[] from your mailflatrate account.

you can find our private policy here[]

you can find our legal policy here[]


  • Connect plugin to mailflatrate server using api keys.
  • Create own form using html editor or click on field button
  • Save custom html form.
  • you can set messages for success and error both.
  • user can submit email and it will automatically add mailflatrate list.


Installing the plugin

  1. In your WordPress admin panel, go to Plugins > New Plugin, search for Mailflatrate and click “Install now
  2. Alternatively, download the plugin and upload the contents of to your plugins directory, which usually is /wp-content/plugins/.
  3. Activate the plugin
  4. Set your API key in the plugin settings.

Configuring Sign-Up Form(s)

  1. Go to Mailflatrate > Forms
  2. Select at least one list to subscribe people to.
  3. (Optional) Add more fields to your form.
  4. Embed a sign-up form in pages or posts using the [mailflatrate] shortcode.


How to display a form in posts or pages?

Use the [mailflatrate] shortcode.

Where can I find my API key to connect to Mailflatrate?

You can find your API key here after register in your mailflatrate account

How user data will send to mailflatrate account list?

your data will be send by mailflatrate api keys using curl method.

The form shows a success message but subscribers are not added to my list(s)?

If the form shows a success message, there is no doubt that the sign-up request succeeded. Mailflatrate could have a slight delay sending the confirmation email though, please just be patient.

How can I style the sign-up form?

You can use custom CSS to style the sign-up form if you do not like the themes that come with the plugin. The following selectors can be used to target the various form elements.

.mailflatrate-form { ... } /* the form element */
.mailflatrate-form p { ... } /* form paragraphs */
.mailflatrate-form label { ... } /* labels */
.mailflatrate-form input { ... } /* input fields */
.mailflatrate-form input[type="checkbox"] { ... } /* checkboxes */
.mailflatrate-form input[type="submit"] { ... } /* submit button */

You can add your custom CSS to your theme stylesheet.

I’m getting an “HTTP Error” when trying to connect to Mailflatrate

If you’re getting an HTTP Error after entering your API key, please contact your webhost and ask them if they have PHP CURL installed and updated to the latest version (7.58.x). Make sure requests to are allowed as well.

My question is not listed

Please feel free to contact mailflatrate support[] from your mailflatrate account.


June 5, 2019
Über das mailflatrate Plugin konnte ich Rechtssicher Abonnenten für meinen newsletter gewinnen. Mich hat der deutsche Server Standort von mailflatrate überzeugt. Ich bin sehr zufrieden!
Read all 2 reviews

Contributors & Developers

“mailflatrate” is open source software. The following people have contributed to this plugin.


Translate “mailflatrate” into your language.

Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.