Trumail - Free email verification API
Mati - Online identity verification platform for fast-growing companies. Increase safety on your product, and comply with KYC / AML regulations.
Proofy - Quickly validate and verify your email lists.
NoPass.me - Open-source identity verification
ZeroBounce - Removes invalid emails from your list to prevent email bounces from ruining your deliverability.
RapidVerify - Verify identity/income instantly.