NeverBounce - Real-time email verification and cleaning to ensure emails never bounce.

Bitrix24 - Bitrix24 is a free (for small businesses) social enterprise platform. It is a united work space which handles the many aspects of daily operations and tasks. Create your own social intranet in minutes!

Email List Verify - The Fastest Way to Improve Email List Deliverability and ROI

EngageBay - EngageBay is an affordable all-in-one marketing, sales CRM and service helpdesk software for growing companies to acquire, engage and nurture web visitors to happy customers.

ZeroBounce - Removes invalid emails from your list to prevent email bounces from ruining your deliverability.

SendX.io - SendX (https://sendx.io) provides remarketing and retargeting tools for web businesses. You can use popups, landing pages, email, web push notification, automation workflows and FB / Google retargeting to drive more revenue.