Yarick

This plugin notifies user if browser check failed. Available checks:
<ul>
<li>Browser version (Chrome, Firefox, Safari, Opera, IE)</li>
<li>JavaScript enable</li>
<li>Cookie enable (require JavaScript)</li>
<li>Adobe Flash Player version (require JavaScript)</li>
</ul>
You can select style for notice. Or disable plugin CSS and write own.
User can close notice to time you set in minutes. It use cookie. You can disable close button.
Also you may set next check time in days. When check is successful.
Browser Check may be integrated with theme. Just place this code: “do_action(‘browser_check’)” in your theme. And disable plugin css from “Settings -> Browser Check” page and write own css for best look in your theme.
Supported languages
<ul>
<li>English</li>
<li>Russian</li>
</ul>

Browser Check

Check browser version, JavaScript, Cookie, Adobe Flash Player version. Warn user if old.

AcyMailing Newsletter Team

AcyChecker is a mailing list cleaning service (email checker) created by the AcyMailing (a WordPress newsletter plugin) team.
This email checker allows you to improve the deliverability of your emails, to reduce your costs or to keep a good reputation by using its WordPress (or Joomla) plugin or its API.
This email checker allows the verification of emails at different levels:
<ul>
<li>Domain and SMTP check</li>
<li>Role email checker</li>
<li>Disposable email checker</li>
<li>Free provider</li>
<li>Email format checker</li>
<li>In-depth tests</li>
</ul>
Why should you clean up your mailing list with an email checker?
1 – Improve deliverability 
2 – Have a good reputation 
3 – Reduce your costs 
4 – Improve your open rates 
5 – Avoid bounces

Anti Spam and list cleaner – AcyChecker

Block fake accounts and delete users using a fake email address

Browser Check vs Anti Spam and list cleaner – AcyChecker