Can I build my own Mailchimp with AI?

Build a minimal email newsletter tool similar to Mailchimp, broadcast only, no automations.

**Objective:** Let an admin collect email subscribers, compose a newsletter, and send it to everyone who hasn't unsubscribed.

**Target user:** A founder or creator who wants a dead-simple newsletter tied to their own site, and understands deliverability basics.

**Core functionality:**
- Public signup form (email + optional first name)
- Double opt-in OR single opt-in with clear consent checkbox (configurable)
- Admin: subscriber list with status (active, unsubscribed)
- Admin: compose campaign (subject line + HTML or markdown body)
- Send campaign to all active subscribers via email API
- One-click unsubscribe page (tokenised URL, no login required)
- Store send history (campaign title, sentAt, recipient count)

**Pages/screens:**
- Public signup form (embeddable component or standalone page)
- Unsubscribe confirmation page
- Admin login
- Admin: subscribers table with search and export CSV
- Admin: compose + preview + send campaign
- Admin: campaign history

**User flows:**
1. Visitor submits signup form with consent checkbox
2. System saves subscriber as pending or active (based on opt-in mode)
3. Admin writes newsletter and clicks Send
4. System batches emails through provider API with unsubscribe link in footer
5. Recipient clicks unsubscribe → status updated, no future sends

**UI direction:**
- Clean admin dashboard, no need to replicate Mailchimp's visual email builder
- Markdown or rich-text editor for email body
- Mobile-friendly signup form

**Data model:**
- Subscriber: { id, email, firstName?, status, consentAt, unsubscribeToken, createdAt }
- Campaign: { id, subject, bodyHtml, sentAt?, recipientCount?, createdAt }

**Authentication:** Admin-only login. Subscribers managed via tokens for unsubscribe.

**APIs/integrations:**
- Resend, Postmark, or SendGrid for sending
- Domain verified with SPF, DKIM, DMARC (document setup steps in admin)

**Responsive requirements:** Signup form and unsubscribe page must work on mobile.

**Error states:** Duplicate email signup → "You're already subscribed"; send failure → log errors, show partial success count; invalid unsubscribe token → friendly error.

**Compliance (MVP):**
- Include physical mailing address or company name in email footer
- Working unsubscribe link in every email
- Store consent timestamp

**Deployment:** HTTPS required. Configure email provider webhook for bounces (optional v2).

**Explicit exclusions:** No visual drag-and-drop email designer, no automation workflows, no segmentation beyond active/unsubscribed, no A/B testing, no open/click tracking in v1.

**Suggested implementation order:**
1. Subscriber model + signup form
2. Admin auth and subscriber list
3. Email provider integration with test send
4. Campaign compose and batch send
5. Unsubscribe flow and DNS setup guide in admin