Best email verification API for AI agents
Short answer
Early results only. ZeroBounce Validation (ZeroBounce) has the highest score for telling whether an email address is deliverable: 100.0 out of 100 in all regions, from 2 test results in the week of 2026-11-09. 3 tools were scored on the same cases. Arettic runs it with one key and charges only when the result passes the check. Scores firm up once each tool has 30 test results.
This week's ranking
| # | Tool | Score | Accuracy | Pass rate | Reliability | Test results |
|---|---|---|---|---|---|---|
| 1 | ZeroBounce Validation · ZeroBounce | 100.0 | 100.0% | 100.0% | 100.0% | 2 |
| 2 | MillionVerifier · MillionVerifier | 96.0 | 100.0% | 100.0% | 100.0% | 1 |
| 3 | Abstract Email Validation · Abstract · Not on sale yet | 15.0 | 0.0% | 0.0% | 100.0% | 2 |
Which one to pick
- Highest scoreZeroBounce Validation
- Most accurateZeroBounce Validation
- Most reliableZeroBounce Validation
- FastestZeroBounce Validation
How we tested
A result passes if: the verifier returns a definitive status (valid or invalid). Unknown or timeout counts as a fail.
Every tool runs the same private test cases with known answers. Live calls from the last 28 days, audits and disputes count too. No provider pays to be included or sees the test set. The formula and every input are public. Scores and the formula.
Used for: Cleaning a list before a campaign, sign-up and CRM hygiene.
Use it from your agent
Ask Arettic which tool leads, then run it. One key covers every tool, with no account at each provider.
# MCP (Claude Code; other clients on /mcp)
claude mcp add arettic --env ARETTIC_API_KEY=sk_test_… -- npx -y @arettic/mcp
# HTTP: which tool leads, then run it
curl -X POST https://api.arettic.com/v1/recommend \
-H "Authorization: Bearer sk_test_…" -H "Content-Type: application/json" \
-d '{"task_type":"verify_email"}'
curl -X POST https://api.arettic.com/v1/execute \
-H "Authorization: Bearer sk_test_…" -H "Content-Type: application/json" \
-d '{"tool_id":"zerobounce-verify-email","input":{"email":"[email protected]"}}'Questions
- What is the best email verification API for AI agents?
- Early results only. ZeroBounce Validation (ZeroBounce) has the highest score for telling whether an email address is deliverable: 100.0 out of 100 in all regions, from 2 test results in the week of 2026-11-09. 3 tools were scored on the same cases. Arettic runs it with one key and charges only when the result passes the check. Scores firm up once each tool has 30 test results.
- How is the score worked out?
- Every tool runs the same test cases each week. The score combines accuracy, pass rate, audit precision, reliability, speed and upheld disputes. The formula and every input are public on the scores page. Paying never changes a score.
- Do I need an account with each provider?
- No. One Arettic key runs every tool. Arettic holds the provider accounts and keys.
- What do I pay when a lookup fails?
- You pay only for what passes the check. It passes if: the verifier returns a definitive status (valid or invalid). Unknown or timeout counts as a fail.
- Can my agent pick the tool itself?
- Yes. Call recommend with task_type verify_email for the ranked list, then execute the tool you want. Both work over the HTTP API and the MCP server.