Kingmailer WordPress SMTP


Kingmailer WordPress SMTP: the #1 WordPress SMTP plugin

Since 2017 Kingmailer WordPress SMTP has powered thousands of websites worldwide in delivering emails to users’ inbox.

Kingmailer’s mission is affordable SMTP for Everyone. We are working day and night to give the highest quality SMTP email delivery service to everyone.

Kingmailer WordPress SMTP plugin contains the important settings fields to manage your SMTP. You will need to add/verify your domain first in your Kingmailer-account.


While you can use our service for free. This will help you save a lot in monthly costs and at the same time help you deliver your emails to users’ inbox. You can Buy SMTP with Bitcoin.

Kingmailer WordPress SMTP is the most trusted email delivery platform by developers, webmasters, small business and startup owners.


Kingmailer is packed full of features, designed for you to see all your email traffic, inbound and outbound email traffic. By going into your Kingmailer account you get access to all sorts of information. Some features are:

  • Real-time results
  • Email statistics
  • Webhooks & integrations
  • Flexible SMTP APIs
  • Optimal delivery
  • Message archive & Logs


We are a transactional only WordPress SMTP email service, this means high inbox delivery.

If your emails land in the junk / spam folder, check the following:

  • Is your domain or IP blacklisted?
  • Does your domain have a poor sending reputation?
  • Is there some configuration error on your web server?


Kingmailer is powered by a team of expert developers, sysadmins and SMTP consultants. They work constantly to stay at the cutting edge of WordPress SMTP and to improve the plugin with every release.

Kingmailer WordPress SMTP is the only WordPress SMTP plugin made by world-renowned SMTP experts.


  • Configuration options for using the Kingmailer HTTP API


Starting with Kingmailer WordPress SMTP consists of just two steps: installing and setting up the plugin. Kingmailer WordPress SMTP is designed to work with the wp_mail functionality and will relay all emails.


  1. Visit the plugins page within your dashboard and select ‘Add New’;
  2. Search for ‘Kingmailer WordPress SMTP’;
  3. Activate Kingmailer WordPress SMTP from your Plugins page;
  4. Go to ‘after activation’ below.


  1. Upload the ‘kingmailer-smtp’ folder to the /wp-content/plugins/ directory;
  2. Activate the Kingmailer WordPress SMTP plugin through the ‘Plugins’ menu in WordPress;
  3. Go to ‘after activation’ below.


  1. You should see Settings button;
  2. Go through the settings page and set up the plugin for your site;
  3. You’re done!


Can I use Kingmailer WordPress SMTP to send spam/bulk marketing newsletters?


Can I use Kingmailer WordPress SMTP to send marketing newsletters?


What types of emails are allowed with Kingmailer WordPress SMTP?

Currently only transactional emails.

What are transactional emails?

These are emails usually generated by your WordPress site, some examples are:

  1. Account alerts (subscription ending, credit card expiring, etc.)
  2. Abandoned cart notifications
  3. Event notifications
  4. Order confirmations and purchase receipts
  5. Responses to customer service inquiries
  6. Password reminders or resets
  7. Requests for feedback
  8. Subscription welcome emails

Which fields are in the Kingmailer WordPress SMTP plugin?

The Kingmailer WordPress SMTP plugin is very simple and has the following fields:

  1. Your domain
  2. From name
  3. From address
  4. API-key

Do I need a Kingmailer account to make this work?


How or where do I get a Kingmailer account?

  1. Visit click on sign up.
  2. Click on the link in the activation email to activate your account
  3. You now have a Kingmailer-account.

How much does Kingmailer cost?

Kingmailer, in case you will upgrade, only costs $5 p/mo, you can sign up and test for free. No credit card required.

Does Kingmailer WordPress SMTP work with WooCommerce?

Yes. Kingmailer WordPress SMTP works perfectly with WooCommerce.

Which plugins work with Kingmailer WordPress SMTP?

Elementor Forms
Contact Form 7
Gravity Forms
Fast Secure Contact Form
Visual Forms Builder
Contact Form Builder
PlanSo Forms
MyMail Newsletter by revaxarts
SendPress Newsletters
Email Templates
WordPress Leads

All plugins that uses the WordPress API wp_mail to send emails.

Which port does Kingmailer support?

The Kingmailer WordPress SMTP plugin is designed for port 587. Other ports that we support are 25, 2525 and 465.

Is the connection encrypted?

Yes. All emails are encypted with TLS.

Does Kingmailer also accept Bitcoin?


Testing the configuration fails when using the HTTP API

Your web server may not allow outbound HTTP connections. Set Use HTTP API to “No”, and fill out the configuration options to SMTP and test again. A different possibility may be: your server IP is blocked by Spamhaus or other services that regulates spam. Please check if your IP is not blacklisted.

Can Kingmailer WordPress SMTP be configured globally for WordPress Multisite?

Kingmailer WordPress SMTP plugin is not yet tested with WordPress Multisite.

The plain text alternative of my mail looks different from my template

Plain text alternatives are for mail clients that cannot process HTML. As such, html tags are stripped from the plain text alternative. This is done before applying the wp_mail filters.

How do I get support?

Feel free to send us an email or start a topic in the support forum.


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Registre de canvis

0.3.10 (2022-06-12)
* Tested with new WP version

0.3.09 (2021-07-31)
* Tested with new WP version

0.3.08 (2021-02-06)
* Attachment fix

= 0.3.07 (2020-12-12)::
* Remove SMTP functionality

= 0.3.0 (2020-11-28):
* Add SMTP functionality

0.2 (2020-11-22):

  • Updated text

0.1 (2020-10-17):

  • Initial Release