Open-Source Waitlist & Newsletter Software: A Practical Guide

Open-source tools for collecting emails, running waitlists, and sending newsletters have matured. You can deploy a minimal pre-launch form in minutes, then graduate to high-throughput sending or full marketing automation—while keeping ownership of your data and stack. This guide profiles the most capable projects, how they differ, and how to combine them into a reliable pipeline.

Core newsletter platforms (self-hosted)

These are production-grade systems for subscriber management, segmentation, templating, and delivery reporting.

Project	Stack	License	Notable strengths	Typical use
Listmonk	Go + Postgres	AGPL-3.0	High throughput, single binary, SQL segmentation, APIs/webhooks	Scalable sending with low ops
Keila	Elixir	AGPL-3.0	Visual block editor + Markdown/MJML, double opt-in, bounce/complaint handling, captcha options	Creator-friendly newsletter UX
Mailtrain v2	Node.js + MySQL/MariaDB	GPL-3.0	Ships with Zone-MTA, MJML templates, granular permissions/namespaces	All-in-one self-hosting (including MTA)
SendPortal	Laravel/PHP	MIT	Workspaces, campaign tracking, SES/Mailgun/Postmark/Sendgrid/Mailjet integrations	PHP/Laravel shops wanting permissive licensing
Ghost	Node.js	MIT	Publishing + memberships + newsletters, labels/tiers, strong editor	Content-led brands/publications
Mautic	PHP	GPL-3.0	Marketing automation, visual campaigns, scoring, forms/landing pages	Complex lifecycle and multi-step nurturing

Selection notes

Choose Listmonk when high performance and minimal infrastructure are priorities.
Choose Keila for an approachable UI and solid deliverability fundamentals without heavy automation.
Choose Mailtrain v2 if you prefer bundled MTA and multi-user controls on premises.
Choose SendPortal for Laravel alignment and a permissive license.
Choose Ghost when your newsletter is an extension of a publication or membership site.
Choose Mautic if you require campaign graphs, lead scoring, and advanced segmentation beyond standard newsletters.

Lightweight waitlist builders (prelaunch)

Designed to get a credible “join the waitlist” page live quickly.

Quick Waitlist (Next.js + Resend): one-click deploy, React Email templates, straightforward branding and validation.
Waitlist Kit (Supabase + Vercel): Postgres + Auth foundation, easy CSV export, cohort gating.
Next.js + Notion Waitlist Template: Notion for copy, API route for form handling, optional Redis-based rate limiting, Resend for confirmations.
Makerkit Waitlist Plugin (for Next.js SaaS Starter): drop-in module if you already use Makerkit; consistent design system and auth.

How teams use these: capture emails immediately; store minimal fields (email, consent, source). Later, push contacts to a newsletter engine (Listmonk/Keila/Ghost/Mautic) via API for sending and segmentation.

Referral-capable waitlists (positioning and sharing)

MERN Realtime Wait-list: queue position plus unique referral links; users advance when referrals sign up.
Viral Waitlist API (headless): endpoints for add/confirm/attribute/position; you bring UI, rate limits, and disposable-email filtering.

Operational advice: keep confirmations double opt-in; enforce rate limits by IP/ASN; throttle “you moved up” messages to protect sender reputation.

Operational queue waitlists (venues and services)

Line Me Up (Supabase + React): self-service queue for restaurants/retail; notifications and status tracking.
Queue-Smart (QR-based, MIT): lightweight, QR-first digital queue for small events or clinics.

These target day-of operations rather than prelaunch marketing.

Minimalist, DB-scheduled waitlist/newsletter system: waitlist.onl and `Antibody/waitlist-node-js`

For teams preferring a small, readable codebase with strong database primitives:

waitlist.onl provides a public demo and documentation of a minimal waitlist/newsletter sign-up.
Antibody/waitlist-node-js is the companion open-source implementation (Node.js + Express) using Supabase for storage/auth and Resend for email. A key design choice is database-native scheduling via pg_cron + pg_net:
- Postgres invokes a protected HTTP endpoint on a fixed schedule (bearer token).
- The app stores a canonical launch date and sends one reminder post-launch to contacts with reminder_sent=false.
- Admin access is session-guarded; the allowed admin email is configured explicitly.
- CSV export and a manual-send path are included.

This approach removes the need for an external job runner while keeping the code path for reminders transparent and auditable.

Integration patterns (recommended)

Data flow: Waitlist form → Supabase (email, consent_ts, ip, source) → push to Listmonk/Keila via API (tags like source=waitlist, cohort=beta-1) → send confirmations from the newsletter engine or transactional provider (Resend/SES).
Double opt-in: Always confirm subscriptions; record consent_ts, consent_ip, and method. This protects deliverability and compliance.
Suppression lists: Centralize bounces/complaints/unsubscribes in the sending system; prevent re-imports from re-opting suppressed addresses.
Referrals: Enforce IP/ASN throttles, cap daily referral emails per user, and filter disposable domains. Keep the referral loop secondary to consent quality.
Post-launch migration: Export waitlist CSV with custom fields (join date, referral count). Import to Listmonk/Keila/Mautic, preserving tags and consent metadata.

Deliverability and compliance (essentials)

Authentication: configure SPF, DKIM, and DMARC for the sending domain before any bulk sends.
Warm-up: start with low-volume, engaged segments; increase gradually.
List hygiene: prune hard bounces and repeated soft bounces; process feedback loop complaints immediately.
Segmentation: engage recent signups separately from older or inactive cohorts.
Unsubscribe: single-click link, visible footer placement, immediate suppression.

Deployment notes

Separation of concerns: host the waitlist/front-end on an edge platform (e.g., Vercel); run your newsletter engine (Listmonk/Keila/Mautic) in a container environment (e.g., Fly.io/Render/Cloud Run/Docker on VPS).
Secrets: keep SMTP/API keys server-side; avoid client-side validation of provider keys. If validation UX is required, proxy via short-lived tokens.
Observability: log signups per channel, send rates, bounce/complaint counts, and unsubscribe rates. Track template performance over time.

Recommended starting points

Fastest path to production: a Next.js waitlist template (Quick Waitlist or Waitlist Kit) + double opt-in + Listmonk for sending.
Content-centric teams: Ghost with member labels/tiers; optional handoff to Listmonk/Keila if you outgrow the built-in mailer.
Automation-heavy funnels: Mautic with clear ownership of consent and suppression.
Small, auditable footprint: waitlist-node-js with pg_cron/pg_net scheduling; later, hand off bulk sending to Listmonk/Keila.

Open-source waitlist and newsletter tools cover the full lifecycle: capture interest, confirm consent, engage at scale, and automate when needed—all under your control. Start with a minimal form and clean consent records; add a dedicated newsletter engine as the list grows; adopt automation only when it’s justified by workflow complexity. The projects above are stable choices with clear integration paths and predictable operations.