Free Cold Email
Tools.
Professional-grade cold email tools, free to use. Audit your SPF/DKIM/DMARC, scan copy for spam triggers, and narrow your ICP in seconds. No signup — built by engineers who deploy cold email infrastructure for US B2B teams.
Segment Generator
Generate Top 3 segments for your niche.
DNS Audit
Is your domain leaking revenue? Scan for SPF, DKIM, and DMARC errors that send you to spam.
Spam Checker
Paste your script. We'll identify the subtle trigger words that kill your deliverability rates.
Which Tool Should You Use First?
Each tool solves a different piece of the cold email stack. The order you run them in matters.
Start with the DNS Checker
Run this first. If your SPF, DKIM, or DMARC is broken, nothing else matters — even the best copy lands in spam. Audit your domain, fix what's flagged, re-run until you see 90+.
Narrow your ICP with the Segment Generator
Before you spend on Apollo credits, make sure you are sending to the right 500 people — not the wrong 5,000. Get three targeted ICP segments for your niche in seconds.
Polish copy with the Spam Trigger Checker
Once infrastructure and ICP are solid, run your draft through the spam checker to catch the subtle trigger words that still cost you placement.
Why We Built These Tools
We run cold email infrastructure builds for US B2B clients. Every new engagement starts with the same three audits: does the domain authenticate cleanly, is the ICP narrow enough to pull a 5%+ reply rate, and does the copy stay out of spam-trigger territory.
These three tools are the audits. We opened them up publicly so founders can self-diagnose before spending money on infrastructure setup, agency retainers, or yet another sending tool.
If all three come back clean and your cold email still isn't working, the problem isn't here — it's either warmup or your offer. Read our email warmup timing guide or the 2026 benchmarks to see what "working" looks like.
Frequently Asked Questions
Are these tools really free?→
Yes, all three. No signup, no email wall, no usage limits. They are the exact audits we run during client onboarding — opening them publicly costs us nothing and helps founders diagnose problems without us.
Why do I need to audit DNS if I already use Gmail?→
Because Gmail's default setup doesn't cover everything cold email needs. You still have to publish SPF, DKIM, and DMARC records at your domain's DNS provider — Gmail doesn't do that for you. Since February 2024, Gmail and Yahoo require DMARC on any sender above 5,000 messages/day.
Will these tools alone get me to inbox?→
They are necessary, not sufficient. Clean DNS + good copy + narrow ICP is the foundation. You also need secondary domains (so you don't burn your primary), proper warmup (14–42 days), and a sender like Instantly or Smartlead. The tools catch the first 60% of problems; the rest is infrastructure.
Do these tools work for Microsoft 365 as well as Google Workspace?→
Yes. The DNS checker has a Microsoft selector option. The copy checker and ICP generator are platform-agnostic. If you're deciding between the two, read our Workspace vs M365 comparison.
Is there a catch? Why are you giving these away?→
No catch. TenX charges a one-time fee to build cold email infrastructure for clients who want the full system — domains, inboxes, Apollo, Instantly, all owned by them forever. The tools help founders who can DIY; they also help us prove we know what we're doing when someone is evaluating whether to hire us.