Refuse fake, mistyped and disposable email addresses in your WordPress forms with the MailTester Ninja Email Verification plugin. Each address is checked in real time against the recipient's mail server when the form is sent, without sending any email. If it does not exist, the visitor sees a message under the field and can correct it before submitting.
Install the plugin
The plugin is listed in the WordPress.org directory. In your dashboard, open Plugins, then Add New Plugin, search for MailTester Ninja, then click Install Now and Activate. Updates then arrive in your dashboard like for any other plugin.
See the plugin on WordPress.org
The directory can take a few days to show a new plugin in search results. Until then, open the plugin page above and click Download, or use our ZIP file (version 1.0.0), then upload it in Plugins, Add New Plugin, Upload Plugin.
Where it works
- Contact Form 7: email fields.
- WPForms: email fields, with or without the confirmation field.
- Gravity Forms: email fields.
- WooCommerce: the checkout, both the classic checkout and the Checkout block, and account registration.
- WordPress: user registration, comments and product reviews from visitors who are not logged in.
Each place can be switched on or off in Settings, then MailTester Ninja.
Set it up in two minutes
- Install and activate the plugin.
- Get a key: a free API token (50 checks a day, one every 30 seconds) or a paid key for busier forms.
- Open Settings, then MailTester Ninja, paste the key and save.
- Use Test an address on the same page to see the verdict your forms will apply.
What is refused
| Verdict | Default |
|---|---|
| Address rejected by its mail server | Refused |
| Domain that cannot receive email | Refused |
| Disposable address | Refused, can be switched off |
| Catch-all domain (accepts every address) | Accepted, can be refused |
| Full mailbox, temporary error, server that cannot be checked | Always accepted |
If MailTester Ninja does not answer within the delay you choose (10 seconds by default), the address is accepted: your forms never stop working because of the verification. The settings page shows the last problem met, such as an expired key.
Privacy
Only the email address is sent, when the form is submitted. We keep no copy of the addresses you verify. The plugin keeps verdicts for up to a week in your own database, under a hashed key, so the same address does not use your quota twice, and it adds a paragraph to the privacy policy guide of WordPress.
Questions
Does it send an email to the address?
No. The check talks to the recipient's mail server and stops before any message is sent.
Will it refuse real customers?
Only addresses that the mail server rejects, domains without a mail server and, if you keep the option, disposable addresses. You can also list domains or addresses to always accept.
Which key should I use?
A free API token is enough to try the plugin and for small sites. For busier forms, a paid key allows 100,000 checks a day or more.
Try it now
Get a free API token, or see the plans for up to 200,000 checks a day. Full reference: API documentation. Back to all integrations.