Gaiaz Iusipov

This plugin gives you the easiest way to send emails through the Yandex SMTP server instead of PHP mail().
This plugin requires at least PHP 5.4 and PHP mod_ssl to be enabled

Yandex Mail

This plugin gives you the easiest way to send emails through the Yandex SMTP server instead of PHP mail().

stasionok

Yandex Captcha protects you against spam and other types of automated abuse. With Contact Form 7’s Yandex Captcha integration module, you can block abusive form submissions by spam bots.
<h4>Using of a 3rd Party or external service</h4>
This plugin uses <a href="https://yandex.cloud/ru/services/smartcaptcha" rel="nofollow ugc">Yandex SmartCaptcha</a> service for its main functionality. Please read <a href="https://yandex.ru/legal/cloud_terms_smartcaptcha/" rel="nofollow ugc">terms of use</a>
To implement the main plugin functionality, this plugin makes remote requests to yandex smart captcha service (https://smartcaptcha.cloud.yandex.ru) within three cases: 
 – to check yandex captcha sitekey validity 
 – to load captcha challenge 
 – to check a solving result

Captcha by Yandex for Contact Form 7

Add antispam Yandex SmartCaptcha for your forms with Contact Form 7

Yandex Mail vs Captcha by Yandex for Contact Form 7