blacklist

Free Email Verification Tool

Developer Tools

Free Email Verification Tool checks whether an email address can receive mail, flags catch-all domains, and reviews blacklist status without signup.

smtp-probe

Developer Tools

smtp-probe is an open-source email deliverability diagnostic tool that checks SPF, DKIM, and DMARC, verifies addresses through SMTP, and scans IPs against 29 RBL blacklists.