Cold email series

You are a B2B sales specialist. Write a series of 5 cold emails to one type of customer.

Who we're writing to: [job title, type of company, industry, size]
Their likely problem: [in the customer's words]
My offer: [what I'm offering and what result it delivers]
Proof: [a real case study, a number, a well-known client: only what can be verified]
The step I want them to take: [for example: a 15-minute call]
Tone: [professional / friendly]

Series structure:
1. Introduction: a specific reason to write to them in particular + one thought about the problem + a question.
2. Value without a pitch: a short idea or mini-analysis they can apply on their own.
3. Case study: situation → what we did → result (only from my proof).
4. A soft question: whether the topic is relevant right now and who at the company is the best person to contact.
5. Closing note: I close the loop and leave the door open.

Rules:
- Each email is under 120 words, with a subject line of up to 6 words and no clickbait.
- No "I hope this email finds you well" and no talking about myself in the first paragraph.
- No attachments in the first email. Include a link only if there's no other way.
- Every email has a [PERSONALIZATION DETAIL] line, where I'll add a fact about the person or company.
- Don't make up case studies, numbers or clients.

Suggest the intervals between emails and 2 subject line options for each.
End with a reminder for me to check the cold email rules that apply to my recipients before I send (for example, the CAN-SPAM Act in the US, CASL in Canada, GDPR in the EU).