BounceBlock.io
Free tool

Email Server Tester

Enter a domain to see its MX records and the mail provider behind them. Advanced mode resolves each server's IP and reverse DNS — the signals receivers judge a sender by.

How it works

  1. 1Enter a domain (e.g. yourcompany.com).
  2. 2We query its MX records live and identify the provider.
  3. 3Advanced: resolve each mail server's IP and PTR (reverse DNS).
Questions

Frequently asked

What does this tell me?

Whether a domain has working mail servers, who hosts them, and (in Advanced) whether those servers have proper reverse DNS — a common deliverability signal.

Can it test SMTP directly?

Browsers can't open SMTP connections, so this runs over DNS. For a full inbound send test, pair it with our deliverability and blacklist tools.

Can I check a whole list at once?

This free tool checks one at a time. To verify a full list — email, phone and company together — upload a CSV to BounceBlock and preview your first 100 rows free.

Stop wasting hours on dead leads.

Upload your list and see how clean it really is — free, in under two minutes.

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