Free tools for cold email senders
100% free. No sign up. No sign in. Runs in your browser.
A growing set of free tools for cold email senders. Every tool runs in your browser, requires no signup, and never sends your data anywhere except the Cloudflare public DNS endpoint when domain lookups are needed.
- Inspect email authentication DNS and an explicit sending IP.
Inspect published SPF, DKIM, and DMARC records and optionally check an explicit public sending IPv4 against four current DNS blocklist zones. - Query eight DNS record types for one exact name.
Query A, AAAA, MX, TXT, CNAME, NS, SOA, and CAA for one exact name through Cloudflare DNS over HTTPS. - Decode SMTP replies without guessing beyond the diagnostic.
Parse standard 4xx and 5xx SMTP replies, including enhanced status codes, with conservative next steps. - Inspect authentication evidence and unsubscribe header structure.
Inspect the topmost authentication results, visible Received path, and RFC 8058 one-click header requirements. - Review a subject line with transparent content heuristics.
Review length, capitalization, punctuation, promotional wording, and unresolved merge fields without a fabricated spam verdict. - Preview sanitized HTML without remote resource requests.
Inspect sanitized email HTML in sandboxed Gmail, Outlook, and Apple Mail visual skins without loading remote resources. - Test spintax against the real campaign expansion rules.
Generate up to ten sampled variants with the same five replacement passes used by the campaign renderer. - Generate structurally valid RFC 8058 one-click fields.
Generate List-Unsubscribe and List-Unsubscribe-Post fields from an HTTPS endpoint, with an optional mailto fallback. - Turn HTML into a plain-text body draft.
Create an editable plain-text body draft from HTML while preserving basic structure and safe link targets. - Email planning arithmetic with visible assumptions.
Calculate user-supplied volume plans, illustrative ramps, funnel counts, bounce counts, and two-proportion A/B sample size.