Free email tools
Check a domain's mail setup and read what a message went through. These tools run in your browser: DNS lookups go straight to Cloudflare's public resolver, and nothing you enter is sent to us.
MX lookup
The mail servers for a domain in priority order, with their addresses.
Open →FreeDNS lookup
A, AAAA, MX, TXT, NS, CNAME, CAA and SOA records for any name.
Open →FreeSPF checker
Validate SPF, expand every include and count lookups against the limit of 10.
Open →FreeSPF generator
Pick your sending services and get a valid SPF record to publish.
Open →FreeDMARC checker
Read a DMARC policy, its reports and alignment, and what to fix.
Open →FreeDMARC generator
Write a DMARC record with a safe rollout from none to reject.
Open →FreeDKIM checker
Find a DKIM key by selector, or try common ones, and check its length.
Open →FreeMTA-STS checker
Check MTA-STS, TLS reporting and BIMI records for a domain.
Open →FreeEmail header analyzer
Paste headers to see the route, delays and SPF, DKIM and DMARC results.
Open →Coming soon
Tools that need a server to reach the network on your behalf.
SMTP server test
Connect to a mail server: banner, EHLO, STARTTLS, certificate and open-relay check.
Blocklist check
See whether a sending IP address or domain appears on common blocklists.
Deliverability test
Send an email to a one-time address and get a report on its authentication, content and reputation.
Bounce-handling test
Send to addresses that bounce in different ways and see whether your app handles each one.
Want one of these sooner, or something not on the list? Tell us.
Your DNS is right. Now see how real people react to your email
simmail sends your app's mail to simulated people who open, ignore, junk, click and reply, so you can test what happens after delivery. Start free, no card.