Real‑time SMTP checks, MX/DNS validation, and our proprietary fallback for Gmail, Microsoft, Yahoo, and ProtonMail—the providers that block everyone else.
> verify --email john@acme.com
→ Checking SMTP… connected
→ MX record found (mx.acme.com)
→ Role account? No
→ Disposable? No
→ Gmail fallback: verified
✓ Valid · 98% confidence
Trusted by 2,000+ teams and AI builders
100M+
Emails verified
98.7%
Accuracy rate
<0.1%
Bounce rate
50
Free credits / mo
Every check, every fallback, every result—built for deliverability.
Connect to the recipient’s mail server to confirm the address exists.
Validate domain records to avoid nonexistent or misconfigured mail servers.
Flag catch‑all, role‑based (sales@, info@) and temporary email addresses.
Our unique method for Gmail, Microsoft, Yahoo, and ProtonMail—where others fail.
Upload up to 10,000 emails, verify them in minutes, and download a clean list.
Integrate with your stack or let an MCP agent run verifications autonomously.
Stop verifying one email at a time. Upload a CSV, set your preferences, and let AskOptimus process thousands of emails with the same precision.
Email verification is just the start. Combine it with email finder, AI sequences, and an agent‑ready MCP server—all in one credit pool.
“We replaced three vendors with AskOptimus. The verifier alone saved us hours of manual checking—and our bounce rate dropped to 0.3%.”
— Sarah Chen, Head of RevOps at ScaleFlow
One credit pool for verify, find, send, and AI.
Save 30% with annual billing
No credit card. 50 free credits forever.
Free forever · Cancel anytime · SOC 2 in progress · 7,000+ AI agents already connected