Email Authentication & Deliverability Tools
Check and fix the DNS records that decide whether your mail is trusted: SPF, DKIM and DMARC for authentication, BIMI for brand logos, and MTA-STS and TLS-RPT for encrypted delivery.
When the records look right but mail still lands in spam, send a real message to the deliverability test, test your SMTP server directly, or paste a received message's headers into the header analyzer.
12 free email tools
- SPF CheckerValidate SPF syntax and the 10-lookup limit
- DKIM CheckerLook up and validate a DKIM key by selector
- DMARC CheckerCheck DMARC policy, alignment and reporting
- BIMI CheckerBrand indicators for email
- MTA-STS CheckerEnforced TLS mail delivery
- TLS-RPT CheckerSMTP TLS reporting
- Deliverability TestSend a test email, get a 0-10 score
- SMTP TestConnect, STARTTLS, log in and send through an SMTP server
- Header AnalyzerParse a received email's headers, auth results, and hop delays
- SPF Record GeneratorBuild an SPF record with a 10-lookup check
- DMARC Record GeneratorBuild a DMARC policy record from your settings
- DKIM Key GeneratorGenerate an RSA key pair and DKIM DNS record
Guides: Web & Mail Servers
- Nginx as a Load BalancerThe upstream block, balancing methods (round-robin, least_conn, ip_hash, hash), health checks (passive open-source vs active Plus), retries and failover, keepalive to upstreams, and TCP/UDP load balancing.
Checking a whole domain? The Super Scanner runs every DNS, email, website and security check at once and gives one score.