Email & Deliverability
Build and validate SPF, DKIM, and DMARC DNS records, analyze email delivery headers, and check domain spam blacklist status across 50+ RBLs.
Email Header Analyzer
Email & Deliverability
Paste raw email headers to visualize delivery hops, SPF/DKIM/DMARC authentication results, and detect spoofing.
SPF Record Generator
Email & Deliverability
Build a valid SPF TXT DNS record from IP addresses, domains, and includes. Copy-paste ready output.
DMARC Policy Builder
Email & Deliverability
Create a DMARC DNS record with policy level, reporting addresses, and alignment mode. Prevent email spoofing.
DKIM Key Generator
Email & Deliverability
Generate RSA DKIM key pairs and the DNS TXT record for your mail server. Keys generated securely in-browser.
Email Blacklist Checker
Email & Deliverability
Check if your domain or IP is listed on major spam blacklists (Spamhaus, Barracuda, SORBS, and 50+ others).
MX Record Propagation Checker
Email & Deliverability
Verify MX record propagation across 20+ global DNS servers simultaneously. Diagnose mail routing issues.
About Email & Deliverability Utilities
Eliminate email deliverability failures and prevent domain spoofing. Generate RFC 7208 SPF records, build RFC 7489 DMARC policies, create RSA DKIM key pairs, and analyze raw email headers to resolve spam folder filtering.
Frequently Asked Questions
Why is DMARC authentication mandatory in 2026?
Mailbox providers like Google Workspace and Yahoo require valid DMARC, SPF, and DKIM alignment to prevent phishing and reject unauthenticated transactional emails.
How many DNS lookups can an SPF record cause?
RFC 7208 limits SPF records to 10 DNS lookups maximum. Exceeding 10 lookups causes a PermError and fails email validation.