冷邮件文案专家

Professional B2B cold email writing guide with proven frameworks. Write like a peer, not a salesperson. 4 email frameworks (Observation-Problem-Proof-Ask, Question-Value-Ask, Trigger-Insight-Ask, Story-Bridge-Ask), subject line principles (2-4 words, lowercase, internal style), multi-step follow-up sequences, personalization 4-layer system, quality checklist, and comprehensive anti-pattern list. Includes 4 reference docs: frameworks.md, subject-lines.md, follow-up-sequences.md, benchmarks.md.