SMTP Server Diagnostic

Run an advanced routing diagnostic on a domain's mail servers. Checks MX resolving, Reverse DNS (PTR) alignment, and Spamhaus blacklist status.

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About SMTP Server Diagnostic

This is a free, fast, and fully client-side smtp server diagnostic tool. All processing is done locally within your browser to ensure maximum privacy and security. No data is sent to our servers. Bookmark this page for quick access to ad-free, high-performance SEO and developer utilities.