Should you build your own Mailchimp?

Build me a small-list email campaign tool to replace Mailchimp. Requirements:

- Node + Express + better-sqlite3 on my VPS. Admin UI bound to localhost/VPN; only
  the subscribe and unsubscribe endpoints are public.
- Contacts with tags and custom fields, CSV import and export, and segments saved
  as filters (has tag X, joined after date, opened last campaign).
- Campaigns written in Markdown, rendered into one clean single-column HTML email
  with mjml, plain-text alternative generated automatically.
- Send through Amazon SES (keys in .env) with throttling and per-recipient status;
  SES bounce and complaint notifications auto-suppress those addresses.
- Compliance baked in: unsubscribe link and postal address in every footer, a
  List-Unsubscribe header, double opt-in on the public signup form.
- Open tracking is a per-campaign toggle, default off. Campaign report shows sent,
  bounced, and unsubscribed counts.
- One SQLite file holds everything; no telemetry, no third-party trackers.
- Out of scope: the drag-and-drop template editor, automation journeys, and
  ecommerce integrations. One good template, sent well.
- README warning: inbox placement is earned, not coded. Document SPF, DKIM, and
  DMARC setup and tell me to warm up sending volume gradually.