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Free tools for email and uptime
Check any domain in seconds — email authentication, sender reputation, SSL certificates, uptime and DNS. Every tool tells you, in plain English, what's broken and exactly how to fix it.
These tools read public DNS records and make ordinary public web requests. They're intended for domains and sites you own or manage — please don't use them for unauthorized reconnaissance.
Email deliverability
Will your mail reach the inbox? These check the DNS records receiving servers use to decide.
Email Deliverability Checker
Check SPF, DKIM, DMARC, blacklists and MX in one go.
SPF Checker
Validate SPF, count its DNS lookups, and catch the PermError trap.
DKIM Checker
Verify DKIM signing on the right provider selector.
DMARC Checker
Check DMARC policy strength and the duplicate-record trap.
Blacklist Check
See if your sending IP is on major email blacklists.
Email Deliverability Test
Run a full inbox-readiness test and get one clear verdict.
SPF Record Generator
Build a valid SPF record from your sending sources.
DMARC Record Generator
Build a DMARC record with the right policy and reports.
Website monitoring
Is the site up, is the certificate valid, and has that DNS change landed yet?