Active installations400Adoption metric — not a quality score
WordPress.org ratingNo WordPress.org ratings yet
Official packageDirect from WordPress.org
Repository metrics are context, not quality scores. Active installations measure adoption and can strongly reflect a plugin’s age and historical popularity. Ratings, recent updates and “Tested up to” metadata also do not guarantee modern code, error-free operation, security, feature completeness or suitability for a particular site. Why active installs don’t tell the whole story →
WP PlugIndex currently records Mailster Cool Captcha version 1.4.0 as active, updated 19d ago and tested up to WordPress 7.1.
Overview
About this plugin
Mailster Cool Captcha adds an image-based text captcha to Mailster subscription forms. Visitors type the characters shown in the image before Mailster accepts the signup, which helps reduce automated newsletter spam on your WordPress site.
Use it when you want captcha protection on Mailster forms without connecting to Google reCAPTCHA or other third-party verification services.
>
3 or newer. Captcha images are generated on your server (PHP GD); no external captcha API is required.
Why use Cool Captcha with Mailster?
Self-hosted captcha — Image challenges are created on your site; submissions are checked against a server-side session value.
Per-form control — Choose which Mailster subscription forms require a captcha.
Custom labels and errors — Set the field label and the message shown when verification fails.
Tune the challenge — Adjust image size, format (JPEG/PNG), quality, blur, strike-through line, word length, wave distortion, rotation, and English or Spanish word lists.
Optional skip for logged-in users — Disable the captcha for visitors who are already signed in to WordPress.
Works with GDPR fields — Field order respects Mailster GDPR checkbox placement when enabled.
Click to refresh — Subscribers can reload the captcha image if it is hard to read.
How it works
Install and activate Mailster Cool Captcha alongside Mailster.
Go to Newsletter → Settings → Cool Captcha.
Select the subscription forms that should show a captcha and adjust appearance options.
On submit, Mailster only accepts the signup when the entered text matches the captcha stored for that form.
Prefer Google reCAPTCHA instead? You may also try Mailster reCaptcha for Forms. org.
WordPress.org metadata
Plugin tags
Topics listed for this plugin in the WordPress.org directory.
captcha
forms
mailster
newsletter
spam
Compatibility & maintenance
Compatibility & maintenance
Tested with WP 7.1
Marked as tested with the current WordPress 7.1 release.
Current WordPress releaseWordPress 7.1
WordPress.org Tested up to7.1
Minimum requirementsWordPress 6.0 · PHP not listed
Update activity14 Oct 202619d ago
“Tested up to” is directory metadata supplied by the plugin author. WP PlugIndex does not turn an older declaration into a claim that the plugin is incompatible.
Changes recorded by WP PlugIndex
Recent tracked changes
Version1.3.1→1.4.0
WordPress compatibility6.5.10→7.1.3
Tracking & source
WP PlugIndex tracks public WordPress.org directory metadata and records selected version, compatibility and availability changes as they are detected.
