
Connect your WordPress site to MailerRocket and embed dynamic subscription forms anywhere using a shortcode.
MailerRocket for WordPress lets you connect your site to your MailerRocket email marketing account and embed beautiful subscription forms on any page, post, or widget area using a simple shortcode.
Key Features:
- Connect with your MailerRocket API key
- Create unlimited forms from any of your lists
- Fields are fetched dynamically from MailerRocket (text, email, dropdown, consent checkbox, and more)
- Live form preview before saving
- Embed multiple different forms on the same page
- Success and error messages shown below the subscribe button
- Fully responsive and theme-friendly
Shortcode Usage:
[mailer_rocket_form id="your_form_id"]
External Services
This plugin connects to the MailerRocket API to provide email marketing subscription form functionality.
What the service is and what it is used for:
This plugin communicates with the MailerRocket platform (https://app.mailerrocket.com) to authenticate your account via API key, retrieve your mailing lists and their custom fields, and submit subscriber data when a visitor completes a subscription form.
What data is sent and when:
- On Connect: Your MailerRocket API key is sent to the MailerRocket server to verify your account and retrieve your mailing lists.
- On Form Builder load: Your API key is sent to fetch the available fields for the selected mailing list.
- On form submission: The subscriber’s form data (name, email address, and any other fields included in the form) is sent to MailerRocket to add the subscriber to the chosen mailing list.
No data is sent until the site administrator connects their API key, or until a visitor submits a subscription form.
Service provider:
This service is operated by MailerRocket.
- Terms of Service: https://mailerrocket.com/terms-and-conditions
- Privacy Policy: https://mailerrocket.com/privacy-policy
License
This plugin is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This plugin is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
Screenshots

API Integrations: Users must enter their unique MailerRocket API Key to link their WordPress site to the platform.

Validation: Once a valid key is entered and the "Connect" button is clicked, the plugin confirms the connection (e.g., "Connected! 2 list(s) found"), enabling the form creation features.

Form Creation: Form Creation: Users can click + Create New Form to open a configuration modal.

Form Title: A custom name for internal organization (e.g., "Newsletter Signup"). List Selection: A dropdown menu allows the user to select which MailerRocket mailing list (e.g., "The Email Artist") the form should feed into. Field Mapping: Clicking Load Fields automatically pulls the required data fields from the selected list, such as Email, Full Name, Interest (dropdown), and Consent Checkboxes.

Live Preview: As the form is configured, a real-time preview displays the visual layout, including the input fields and the "Subscribe" button.

Once a form is saved, it is assigned a specific Shortcode.

On the live website, the plugin renders a clean, functional subscription form.

Input Handling: The form supports various field types including text inputs, dropdown selections, and mandatory "Agree" checkboxes for GDPR compliance.

Success Feedback: Upon successful submission, the form displays a customizable success message (e.g., "Thanks for subscribing!") in a green notification bar, confirming the user has been added to the mailing list.
FAQ
Do I need a MailerRocket account to use this plugin?
Yes. This plugin acts as a bridge between your WordPress site and the MailerRocket platform. You will need a valid API key from your MailerRocket dashboard to fetch your lists and sync subscribers.
Where do I find my API key?
Log in to your MailerRocket account, go to Account → API Keys, and copy your key.
Is there a limit to how many forms I can create?
No. You can create as many unique forms as you need. Each form can be connected to the same mailing list or different ones, allowing you to track exactly where your subscribers are signing up from.
How do I add a form to my website?
Once you save a form in the MailerRocket dashboard, a unique shortcode is generated (e.g., [mailer_rocket_form id=”123″]). Simply copy this code and paste it into any Page, Post, or Sidebar using the standard WordPress Shortcode block.
Will this plugin slow down my website?
Not at all. MailerRocket is designed to be extremely lightweight. The heavy lifting—like processing data and sending emails—is handled on MailerRocket’s high-speed servers, ensuring your site’s loading time remains unaffected.
Does the plugin support custom fields?
Yes! When you click “Load Fields” during form creation, the plugin automatically pulls all fields associated with your MailerRocket list, including text inputs, dropdowns, and checkboxes.
Is MailerRocket GDPR compliant?
Yes
What happens if I change my mailing list in MailerRocket?
If you add or remove fields from a list on the main MailerRocket platform, simply go back to your form settings in WordPress and click “Load Fields” again. The plugin will instantly refresh to match your new list structure.
Can I customize the look of the forms?
MailerRocket forms are designed to be clean and professional out of the box. However, they use standard HTML classes, meaning you can easily apply custom CSS through your theme’s “Additional CSS” section to match your brand’s specific colors and fonts.
ChangeLog
2.1.0
- Split into proper multi-file plugin structure
- Fixed compact() bug that broke form saving and subscribe
- Added try/catch error handling on subscribe handler
- Error/success message now appears below the Subscribe button
- Added scrollIntoView so message is always visible
- Moved to top-level admin menu
- Fixed admin CSS enqueue hook for top-level menu pages
- CSS and JS are now separate asset files (properly versioned and cached)
2.0.0
- Multi-form support — create unlimited forms from any list
- Form builder modal with live preview
- Edit and delete forms from admin
- Dynamic field rendering based on MailerRocket list fields
1.0.0
- Initial release
- Single form, single list