Castle - The easiest way to protect your users from getting hacked
Smarty - Smarty provides address validation, autocomplete, geocoding and reverse geocoding services covering addresses in over 240+ countries.
Mail Dump - Powerful Extensions for email addresses extracting, verifying and finding
Loqate - The Standard in Global Address Verification
Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.
Addressy - Addressy is address verification software that captures and verifies addresses on websites.