MARCOM Robot - https://www.marcomrobot.com/
Email Validation Bot performs a series of real-time checks for each email address such as MX record check, SMTP record check, RFC syntax check and many more. You get an overall quality score raging from 0 to 1 for every processed email. Based on the email quality score you can easily build a process of segregating junk leads from those with correct information. Deliver quality leads straight to the Sales team and keep the junk out of your marketing automation and CRM platforms.