Free tools for cold email pros.
Diagnose deliverability issues, verify authentication records, and audit your sending infrastructure — all free, all in your browser, no account needed.
Email Header Analyzer
Paste raw email headers to verify SPF, DKIM, and DMARC authentication, trace the delivery chain hop by hop, and pinpoint exactly why an email landed in spam.
SPF / DKIM / DMARC Checker
Look up SPF, DKIM, and DMARC DNS records for any domain in real time. Validates formatting, counts DNS lookups, decodes every tag, and flags misconfigurations.
Email Blacklist Checker
Check your sending domain or IP against 27 major blacklists in real time — Spamhaus, Barracuda, SpamCop, URIBL, and more. Results stream in as they complete.
Domain Reputation Checker
Get a reputation snapshot for any domain — age, MX records, DMARC policy, and spam history all in one view.
DMARC Policy Analyzer
Decode every tag in a domain's DMARC record — policy, subdomain policy, reporting addresses, alignment modes, and enforcement percentage — with a prioritised fix list.
Inbox Placement Estimator
Estimate your inbox rate at Gmail, Outlook, Yahoo, and Apple Mail based on live DNS signals — SPF, DMARC, PTR, blacklists, BIMI — plus optional subject line spam analysis.
BIMI Record Checker
Validate your BIMI record, verify your logo URL and VMC certificate, check DMARC prerequisites, and see exactly which inboxes will display your brand logo.
DNS Record Inspector
See every DNS record for any domain — SPF, DKIM, DMARC, MX, BIMI, MTA-STS, A, NS and more — grouped, labelled and explained in plain English. Works with any registrar.
SPF Record Generator
Build a valid SPF record in seconds. Select your email providers, add custom includes and IP ranges, choose your enforcement level, and copy the ready-to-publish TXT record.
DMARC Record Generator
Build a DMARC policy record step by step — set enforcement level, reporting addresses, alignment modes, and pct — then copy the ready-to-publish _dmarc TXT record.
DKIM Key Generator
Generate a 2048-bit RSA DKIM key pair entirely in your browser. Copy the public key TXT record for DNS and download the private key PEM for your mail server.
MTA-STS & TLS-RPT Generator
Generate your MTA-STS policy file and DNS records to enforce TLS on all inbound email, plus a TLS-RPT record so you can monitor delivery failures.
Want us to fix the issues these tools surface?
Mailflo handles SPF, DKIM, DMARC setup, domain warmup, and inbox monitoring for you — so your emails always pass every check.
See Mailflo plans