Free Email & Deliverability Tools
Everything between 'send' and the inbox: check your domain's authentication records, validate BIMI, pre-flight campaign HTML before it goes out, and build client-safe signatures. Pair them with free daily Deliverability Monitoring to get alerted the moment a record breaks.
Email Signature Creator
HTML signatures for Gmail, Outlook & Apple Mail
Build client-safe HTML email signatures. 3 templates, brand colors, logo URL, one-click copy or HTML export.
MX Record Lookup
Find mail servers and detect email providers for any domain
Look up MX records for any domain. Identifies the email provider (Google Workspace, Microsoft 365, Proton Mail, etc.), shows all mail servers with priority and TTL, and checks your SPF record — via Cloudflare DNS-over-HTTPS.
BIMI Validator
Show your logo in Gmail, Yahoo Mail & Apple Mail
Validate your BIMI record — check the _bimi TXT record, SVG logo URL, VMC certificate, and DMARC prerequisite. Preview how your logo will appear in the inbox and see exactly what's blocking it.
DNS Email Diagnostics
SPF, DKIM, DMARC, MX, BIMI & MTA-STS in one check
Comprehensive email authentication check for any domain. SPF, DKIM (18 selectors), DMARC, MX, BIMI, and MTA-STS all checked in parallel via Cloudflare DNS-over-HTTPS. Health score, raw records, and fix guidance.
HTML Email Pre-flight Checker
Catch Outlook breakage and spam signals before you hit send
Paste your email HTML and get a 0–100 pre-flight score: client compatibility for Gmail, Outlook, Apple Mail & Yahoo (caniemail data), spam-trigger signals, structure and link checks, plus a simulated dark-mode preview. 100% client-side.
Don't just check once — get alerted when a record breaks
Daily SPF, DMARC, MX & BIMI monitoring with change alerts and a weekly digest. Free during beta.
🔑 Authentication beats content
Since the 2024 Gmail/Yahoo sender rules, SPF, DKIM, and DMARC matter more than any subject-line trick. Run the diagnostics first.
📉 Records break silently
Registrar migrations and teammate edits delete DNS records without anyone noticing — until open rates crater. Monitoring exists for exactly this.
🧪 Test the HTML too
A perfectly authenticated email can still render broken in Outlook. Pre-flight the markup before every campaign.
FAQ
What do SPF, DKIM, and DMARC actually do?
SPF lists which servers may send for your domain; DKIM cryptographically signs each message; DMARC tells receivers what to do when both fail and where to send reports. All three are DNS records — the diagnostics tool checks them in one scan.
Are these email tools free?
Yes — every check runs free without an account. Deliverability Monitoring is also free during beta for up to 3 domains.
Do you see the domains I check?
Lookups resolve public DNS records via Cloudflare DNS-over-HTTPS; only the domain name is queried and results are not stored. Monitoring subscriptions store your email + domain, as described in the privacy policy.
My SPF and DKIM pass — why is mail still going to spam?
Authentication is necessary but not sufficient: sender reputation, list quality, engagement, and content weight the rest. Start with the pre-flight checker for content signals, and check whether your sending IPs sit on a blocklist.