Cold Email Subject Line Tester
by mbfinotti1ef68881b2edMITListed Oct 8, 2026Updated Oct 8, 2026Repository updated 3 weeks ago
Generates, scores, and split-tests email subject lines, producing angle-distinct variants, a numeric scorecard, and a test plan with sample size and decision metric. Covers B2B cold outbound and B2C lifecycle/promotional email, and flags spam-trigger words inside the subject line only. Use whenever the user mentions a subject line, open rates, email A/B test, preview text, or "nobody opens my emails", even if they don't say "subject line" explicitly. Do NOT use for body copy or inbox-placement audits (mbfinotti/sales-skills@cold-email-deliverability), personalization angles (mbfinotti/sales-skills@sales-outreach-personalization), or cadence design (mbfinotti/sales-skills@sales-outbound-sequence).
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npx skills add https://github.com/mbfinotti/sales-skills/tree/1ef68881b2ed853fb1f02272b57dc71dd375677f/skills/cold-email-subject-line-testerSource and attribution
Source:mbfinotti/sales-skillsinskills/cold-email-subject-line-testerat commit1ef6888
License: MIT
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