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Writing Templates5 min read

AI personalization with Claude

Turn on AI personalization and Claude writes a unique, context-aware opening line for every contact — automatically.

Generic bulk email fails because recipients can tell it's bulk email. The most effective outreach feels personal — like it was written specifically for them. CMass's AI personalization uses Claude (Anthropic's AI model) to generate a unique, contextually-relevant opening sentence for every contact on your list.

What Claude writes

Claude generates a 1–2 sentence personalized opener that's inserted at the beginning of your email, before your main template text. It uses all available context about the recipient:

  • ▸Their first name, last name, company, and job title
  • ▸Your email history with them (if they're a CMass contact)
  • ▸Any custom columns in your Sheet or CSV — especially useful fields like 'Custom Note', 'LinkedIn Summary', 'Industry', or 'Recent News'
✅ Get the best results: Add a 'Custom Note' column to your contact list with a one-sentence context for each person — something you noticed about them, a shared connection, or why they're a good fit. Claude uses this to write openers that feel genuinely researched.

How to turn it on

  1. 1Go to the Template tab in the CMass panel
  2. 2Write your subject line and email body
  3. 3Toggle 'AI Personalization' on — you'll see the toggle turn purple
  4. 4CMass will generate personalized openers for each recipient when you launch the campaign

What your template should look like

With AI personalization on, don't start your email with 'Hi {first_name}' — Claude's opener takes care of the greeting. Instead, start your template body from the second paragraph — the main pitch, value prop, or question. Claude adds the personalized first line automatically.

💡 Example: your template body is 'I wanted to reach out because we help B2B SaaS companies reduce churn by 30%...' Claude prepends: 'I noticed Acme recently raised a Series B and is expanding the sales team — congrats on the growth.'

Plan requirements

AI personalization is a Pro feature. On the free plan, the toggle is visible but sending with AI personalization on will prompt you to upgrade.

Does it actually work?

The research is clear: emails with genuine personalization get significantly higher reply rates than generic blasts. The key word is 'genuine' — AI personalization only works when the opener references something real about the person. That's why the quality of your contact data matters. A rich Sheet with thoughtful custom notes produces much better results than a bare list of email addresses.

  • ▸Campaigns with AI personalization typically see 2–3× higher reply rates vs. non-personalized sends
  • ▸The opener must reference something real — fake personalization ('I love your company') performs worse than no personalization
  • ▸The more context you give Claude (via custom columns), the more specific and effective the opener

Try it in Gmail — free

50 emails/day on the free plan. No credit card needed.

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