Free tools
Every email health check, in one place
No account, no card, no email wall on the basic result. Run any check below in about ten seconds.
Pick a check
Start with whichever question you actually have
Not sure where to start? Run the Email Health Check for one grade across the four core foundations.
Email Health Check
freeGrade a domain's MX, SPF, DKIM, and DMARC together, with the most important fixes shown first.
Run this check →Email Bounce Analyzer
freePaste a bounce or SMTP error to identify hard vs soft failure, decode its status, and get the right next action privately in your browser.
Run this check →DMARC Checker
freeSee whether spoofed email pretending to be your domain gets blocked, quarantined, or waved through.
Run this check →SPF Checker
freeCount your SPF DNS lookups against the hard 10-lookup limit, with a full breakdown of every include.
Run this check →DKIM Checker
freeFind active DKIM signing keys by probing common selectors, or check one you already know.
Run this check →MX Lookup
freeSee every mail server a domain is configured to receive email at, in priority order.
Run this check →Blacklist Checker
freeCheck your mail servers against 5 major spam blacklists (DNSBLs) at once.
Run this check →Email Header Analyzer
freePaste raw email headers, get a plain-English breakdown of the SPF/DKIM/DMARC verdicts and delivery path.
Run this check →Compliance Checker
freeCheck the DNS-verifiable parts of Gmail and Yahoo's 2024 bulk-sender rules.
Run this check →SPF Generator
freeBuild a correctly formatted SPF record for any combination of email providers.
Run this check →SPF Flattener
freeResolve SPF includes down to literal IPs to fix a record over the 10-lookup limit.
Run this check →DMARC Generator
freeBuild a DMARC record with a guided policy from none to quarantine to reject.
Run this check →DKIM Generator
freeGenerate an RSA key pair entirely in your browser — your private key never leaves your device.
Run this check →Email Deliverability Check
freeSend a real email and get a graded scorecard for DKIM verification and alignment, SPF/DMARC publication signals, and selected message-level checks.
Run this check →Email Monitoring Revenue Calculator
freeEstimate the monthly and annual recurring revenue your agency or MSP could generate from managed email monitoring.
Run this check →These checks run once. Monitoring never stops.
Every tool above gives you a snapshot. Turn on free monitoring for your first domain and we'll watch it every day, then tell you the moment something changes.
See monitoring plans