Roundcube plugin to enforce reCAPTCHA for users who have too many failed logins.
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Latest commit 95cc25f May 17, 2018

Roundcube plugin rcguard


This plugin logs failed login attempts and requires users to go through a reCAPTCHA verification process when the number of failed attempts go too high. It provides protection against automated attacks.

Failed attempts are logged by IP and stored in a database table. IPs are also released after a certain expire amount of time.


**NOTE:** This plugin requires reCAPTCHA API keys to work properly. They can be obtained from

With Composer

Add this plugin dsoares/rcguard to the require section of your Roundcube composer.json and enable rcguard in the main Roundcube configuration file.

Copy to and modify as necessary.


Place this directory under plugins/ and enable rcguard in the main Roundcube configuration file.

Copy to and modify as necessary.

Use the files under SQL/ to create the database schema required for rcguard. The table should be created in the database used by Roundcube.

Customizing reCAPTCHA

You may customize the theme and size of the widget in the file. For more information about the widget please check the documentation about reCAPTCHA.

The plugin configuration file has several options you may configure, please take at look.

Since May 2018, you can define a proxy (anonymous or authenticated) to request the recaptcha widget.

Supported databases

  • MySQL
  • PostgreSQL
  • SQLite


The original author of this plugin is Denny Lin. I forked it some years ago to use reCAPTCHA v2.0, add the larry skin and because the project issues were taking too long to be answered. Also, the original project is not updated since 2015 and many things have changed in the meantime in Roundcube's API.

I will maintain this project because i need it working with the latest version of Roundcube.

Comments and suggestions are welcome (preferentially via issues).

Email: Diana Soares


This plugin is distributed under the BSD license. Please see rcguard.php for the complete license.

This plugin also contains a PHP library for reCAPTCHA that is distributed under its own license. See the file for the exact details.