What verification actually checks
Modern verification goes beyond regex. It evaluates syntax, domain DNS, mailbox existence where possible, and risk signals such as disposable providers, role accounts, and accept-all domains.
Results are best treated as structured data: overall result, reason, and flags—not a single opaque score.
Build a policy, not a one-off cleanup
Document how you handle deliverable, undeliverable, risky, and unknown results for each channel (product mail vs. marketing).
Test the policy in staging before automating suppressions that could block legitimate customers.