Privacy Policy
Last updated: July 22, 2026
TL;DR — We don't store the emails you verify.
SMTP Probe is a stateless tool. Email addresses are used only for the duration of the SMTP connection and are never written to disk or logged.
1. Information We Process
When you use SMTP Probe, we process the following data transiently:
- Email address you submit — used exclusively to perform the SMTP verification and catch-all detection. Not stored.
- Your IP address — used for rate limiting (100 verifications per day per IP) and abuse prevention. Not stored beyond in-memory cache expiry.
- Browser metadata — standard HTTP headers (User-Agent, Accept-Language) processed by our web server for routine analytics, not sold or shared.
- Browser fingerprint — a visitor ID computed in your browser by the open-source FingerprintJS library, used transiently in-memory for bot/abuse prevention, not stored or shared.
2. How We Use Your Data
- Email addresses are transmitted via gRPC to our verification engine, which performs SMTP-level checks against recipient mail servers. No email content is sent or received.
- IP addresses are used in-memory rate limiters that expire within 30 minutes.
- Verification results are cached for 10 minutes (keyed by email hash, not plaintext) to improve response time for repeat queries.
3. Third-Party Services
- Cloudflare Turnstile — spam/bot protection. Processes your browser session per Cloudflare's Privacy Policy.
- Recipient Mail Servers — during SMTP probing, recipient servers receive connection metadata (our server IP, HELO hostname) per standard SMTP protocol.
4. Data Retention
We retain no personal data. Specifically:
- Email addresses submitted for verification are never logged or stored in any database.
- Rate-limit counters are held in-memory only and expire within 30 minutes.
- Server logs contain request metadata (timestamps, status codes) but not email addresses.
5. Your Rights
Since we do not store personal data, there is no stored data to access, correct, or delete. If you have concerns about data processed during a verification session, please contact us.
6. Cookies
SMTP Probe does not use cookies. Cloudflare Turnstile may set a cookie necessary for its bot-detection functionality, subject to Cloudflare's cookie policy.
7. Contact
For privacy-related inquiries, email support@uspeedo.com.