Free cold email tools
Updated August 2026 // every tool runs in your browser
These are the eight tools we use on client campaigns, published free with no signup. Every one runs entirely in your browser: your email copy and the domains you check are never uploaded to us or stored anywhere.
The short answer: Eight free cold email tools, all running entirely in your browser with no signup: a sending-domain generator and fleet planner, a spam checker covering 1,130 trigger phrases, a copy grader, a mail provider lookup, a deliverability checker, an SPF and DMARC record generator, an email header analyzer and an ROI calculator. Nothing you paste is uploaded or stored.
Cold Email Domain Generator and Fleet Planner
Generates sending domains across six naming families, checks live registration through RDAP, scores each name against a census of 12.9 million business domains, then audits the set you pick for the shared-stem pattern that gets a whole fleet listed together. Includes a planner for how many domains and mailboxes your volume needs.
Cold Email Spam Checker
Scans cold-email copy against 1,130 spam-trigger phrases grouped by urgency, overpromise, money, salesy and list-mail language, highlighted live as you type, plus link, image, capitals, punctuation and subject-line checks.
Cold Email Grader
Grades a cold email against a working playbook: subject-line tests, the 80-word cap, 606 AI-writing tells, 480 fluff phrases, offer structure and the ask, then applies the mechanical fixes in one click.
Mail Provider Lookup
Enter any company domain to identify the mail environment behind it from public MX records - Google Workspace, Microsoft 365 or a security gateway - and what that environment means for legitimate outreach. Runs in your browser, nothing stored, no signup.
Email Deliverability Checker
Checks any domain's MX records, SPF record with its 10-lookup audit, DMARC policy, DKIM selectors, MTA-STS, TLS-RPT and BIMI, graded with the specific fix for each failure.
SPF and DMARC Record Generator
Builds a valid SPF TXT record and DMARC record from your sending providers, counting DNS lookups live against the limit of 10 that silently breaks SPF. Makes no DNS queries at all, so it cannot generate lookup traffic against your domain.
Email Header Analyzer
Paste raw email headers to get the SPF, DKIM and DMARC verdict, a DMARC alignment check across From, Return-Path and the DKIM signing domain, every delivery hop with its delay, and which of 12 security gateway vendors handled the message. Makes no network requests.
Cold Email ROI Calculator
Models pipeline from list size, deliverability, reply rate, meeting rate and close rate, so cost per meeting and break-even reply rate are explicit before you spend.
Rather we ran the whole thing?
We build and run B2B cold email end to end, copy, infrastructure and booking, and get paid on the revenue we help you close.
Apply to work with usFurther reading
The two questions these tools raise most often, answered in full.
Why verified lists still bounce — what a verification pass can and cannot tell you, and why a list that came back 98% valid can still burn a domain.
Cold email infrastructure — how sending domains, mailboxes, SPF, DKIM and DMARC fit together, and the order to set them up in.
Which checker do you need?
Checker, grader, analyzer: the names blur together, so route by the question you are actually asking. Every row runs in the browser and takes under a minute.
Every tool and research asset
All free, all browser-side, no signup. The research assets below are ReplyLead first-party data with methodology and limitations published alongside the numbers.