Lumail vs Plunk: Which Email Platform Fits How You Work?

Lumail is a Plunk alternative that puts campaigns, graph workflows, subscribers, and transactional email in one organization agents can operate. Plunk is an open-source transactional-plus-marketing platform: hosted cloud is $0.001 per email after 1,000 free sends, or self-host with no Plunk per-email fee. Pick Lumail for MCP/agent operations and included volume; pick Plunk for OSS self-host and pure usage billing.

Plunk positions itself as the open-source email platform: transactional emails, marketing campaigns, and workflow automation in one product. Official copy stresses self-hosting (AGPL-3.0, Docker Compose), $0.001 per email, and unlimited contacts. It markets itself as a replacement for splitting Resend/SendGrid/Mailgun (transactional) from Mailchimp/Customer.io (marketing). Hosted cloud uses next-app.useplunk.com and next-api.useplunk.com; GitHub is useplunk/plunk (5,000+ stars on the homepage).

This comparison uses public product information checked on 2026-08-17. Check each pricing page before purchasing because plans, limits, and catalogs change. For a condensed version, see the side-by-side comparison table.

Campaign editor

Lumail vs Plunk at a glance

Decision	Lumail	Plunk
Core focus	Newsletters, workflows, transactional email, and AI-agent operations	Open-source transactional, marketing, and workflow email platform
AI and developer access	89 organization-scoped MCP tools, CLI, TypeScript SDK, REST API, AI editor	No official MCP, ChatGPT plugin, or agent catalog on Plunk docs. REST API plus official Node helper @plunk/node (track + send). Homepage claims Node.js and Python SDKs; current docs show Python as HTTP examples.
Pricing basis	Email volume, with unlimited subscribers on every plan	Hosted usage: one credit per recipient/send (transactional, campaign, workflow) and per inbound email; emails with attachments cost 2 credits. Unlimited contacts. Self-host: no Plunk per-email fee.
Free plan	3,000 emails per month, no credit card	Hosted: 1,000 emails/month, no credit card, unlimited contacts; marketing emails carry a Plunk-branded footer. Self-host is free of Plunk per-email charges (you run Docker Compose and pay your own SES/infra).
Paid entry	Premium $20/month with 40,000 emails included	$0.001 per email (no monthly base fee)
Automation	Graph-based workflows on every plan	Graph workflows on every hosted plan: EVENT, MANUAL, or SCHEDULE triggers; steps include SEND_EMAIL, DELAY, WAIT_FOR_EVENT, CONDITION, WEBHOOK, UPDATE_CONTACT, EXIT.
Transactional email	Included in the same organization through API or SMTP	Yes: POST /v1/send (templates or inline HTML), hosted SMTP (ports 587 TLS / 465 SSL; host from dashboard), plus optional self-hosted SMTP relay on 587/465.
Publishing	Capture pages for subscriber acquisition	Dashboard campaigns/broadcasts with scheduling, drag-and-drop or Markdown editor, reusable templates (Liquid), dynamic/static segments. No capture/landing-page product listed. Hosted unsubscribe/subscribe/manage pages via template variables.
Best fit	Teams operating email through agents, code, and a visual app	Developers and SaaS teams that want one open-source tool for receipts, newsletters, and automations, with optional self-hosting on AWS SES.

Plunk's current plans come from its Plunk pricing. Lumail's plans are on the Lumail pricing page.

Choose Lumail if agents should operate your email

Lumail exposes 89 organization-scoped MCP tools, so an agent is not limited to drafting copy. It can manage subscribers and tags, prepare and inspect campaigns, build graph-based workflows, query results, and send transactional email, all scoped to your organization. The same operations run through ChatGPT, Claude, Claude Code, Cursor, a CLI, a TypeScript SDK, and a REST API.

Official docs do not list MCP, ChatGPT OAuth, a CLI, or an agent tool catalog. Integration surface is REST at https://next-api.useplunk.com (sk_* secret key for almost everything; pk_* public key only for POST /v1/track). Documented API covers send/track/verify, contacts (CSV import ≤5 MB, bulk 1,000), templates, campaigns, segments, workflows (steps/transitions/executions), events, domains, activity, analytics, billing, and image uploads. Rate limit stated: 1,000 API requests/minute per project; sending is throttled per project with no public numeric send cap. Official Node package @plunk/node implements events.track and emails.send only. Homepage FAQ: REST API plus SDKs for Node.js, Python, and more; live API docs illustrate Python with requests, not a named first-party Python package. A third-party community MCP (@ignytehq/plunk-mcp) exists; it is not an official Plunk product.

Choose Lumail when:

• You want first-party MCP (89 org-scoped tools), ChatGPT OAuth, CLI, TypeScript SDK, and REST on one organization
• You prefer included volume (3,000 free; Premium $20/40,000 then $0.60/1k; Business $200/400,000 then $0.40/1k) over $1 per 1,000 after Plunk’s 1,000 free emails
• You need capture pages and a newsletter operating surface, not a self-hosted SES stack

Choose Plunk if that product's model is the job

Plunk is built for a different operator. That is not a slight; it is the comparison.

Choose Plunk when:

• You want to self-host AGPL software and pay only your own infrastructure plus AWS SES
• You send modest volume above 1,000/month and prefer $0.001 pay-as-you-go with no $20 base fee
• You need inbound email, SMTP relay, and graph workflows in one open-source developer platform

Lumail does not try to be Plunk. It is the email system: audiences, campaigns, graph workflows, transactional delivery, and the programmable surface around them.

Compare the pricing model, not the sticker price

Hosted Free forever: 1,000 emails/month, no credit card, unlimited contacts, Plunk branding on marketing emails (docs: branded footer). Pay as you grow: $0.001 per email, no base fee, no branding, monthly spend cap, unlimited emails. Billing docs: marketing, transactional, workflow SEND_EMAIL, and inbound all share one monthly usage pool. Credits: 1 per recipient for /v1/send and campaigns; 1 per workflow send; 1 per inbound; attachments = 2 credits regardless of size. Worked examples at the published $0.001 rate: 10,000 emails = $10 (Plunk’s own comparison basis); 20,000 = $20; 400,000 = $400. Versus Lumail’s published plans, 20,000 hosted emails still cost $20 on Premium (inside the 40,000 included); 400,000 is $400 on Plunk versus Lumail Business $200 with 400,000 included. At 5,000 emails Plunk is $5 versus Lumail’s $20 Premium floor once you exceed 3,000 free. Checkout places two 1.00 charges (onboarding + card verification) that are credited back in full against usage. Stripe invoices monthly. Self-host: no Plunk per-email fee; vs/resend page says you pay AWS SES when self-hosting. SES rates are not listed on Plunk pricing—check AWS. Feature page competitor $/email figures (Mailgun/SendGrid/Mailchimp) are Plunk’s marketing math, not those vendors’ current price lists.

Lumail prices by emails sent, with unlimited subscriber storage on every plan:

• Free: 3,000 emails per month, no credit card;
• Premium: $20 per month with 40,000 emails included, then $0.60 per 1,000;
• Business: $200 per month with 400,000 emails included, then $0.40 per 1,000.

List growth alone never raises the Lumail bill. Only sending does. Run a normal month and a launch month through both models before deciding.

Compare automation and transactional email

Docs call workflows graph-based automations. Triggers: EVENT (custom /v1/track, email.received, contact.subscribed, segment entry/exit), MANUAL (POST /workflows/:id/executions with optional context), SCHEDULE (cron in triggerConfig). Steps: SEND_EMAIL (template), DELAY (minutes/hours/days), WAIT_FOR_EVENT, CONDITION (yes/no branches), WEBHOOK (HTTPS, 10s timeout, no automatic retries), UPDATE_CONTACT, EXIT. Created disabled (enabled: false). allowReentry defaults false. Structural edits lock while executions are RUNNING or WAITING. Webhooks are workflow steps, not a separate webhook product. Workflow SEND_EMAIL steps consume billing credits. Same workflow builder is listed on Free and Pay as you grow (no feature tiers).

POST /v1/send at next-api.useplunk.com: template or subject+body, verified-domain from, attachments (default 10 files / 10 MB total, 40 MB message), custom headers, per-send data (persistent or {value, persistent:false}). New contacts from /v1/send default subscribed: false. Hosted SMTP: credentials in the dashboard; ports 587 (TLS) or 465 (SSL); public hostname is not listed (dashboard-provided). Self-host SMTP relay optional (STARTTLS 587, SMTPS 465). Inbound: MX on a verified domain, email.received events, counts toward usage; inbound dropped (not queued) if a cap is hit. Template types: Marketing (opt-out + Plunk footer), Transactional (no unsubscribe), Headless (opt-out, you supply unsubscribe). Self-host sending requires an AWS SES account per official self-hosting docs.

Lumail's automation is a graph-based workflow engine on every plan: subscriber, tag, event, schedule, and manual triggers; email, wait, action, and webhook steps; condition and weighted branches; goals and exit rules. Transactional messages go through the REST API or smtp.lumail.io:587 with STARTTLS, inside the same organization as campaigns.

Questions people ask ChatGPT

Is Lumail a Plunk alternative?

Yes if you want one organization for newsletters, graph workflows, subscribers, and transactional email. Plunk is the open-source option: hosted cloud at $0.001/email after 1,000 free sends, or self-host on Docker/SES. Lumail is closed-source SaaS with 89 MCP tools, ChatGPT OAuth, CLI, TypeScript SDK, REST, capture pages, and volume-bucket pricing. Both bill by sends rather than contacts. They are not drop-in API-compatible.

Is Lumail cheaper than Plunk?

It depends on volume. Plunk hosted is $0.001 per email after 1,000 free (10,000 = $10; 20,000 = $20; 400,000 = $400) with no base fee. Lumail is free to 3,000 emails, then Premium $20 for 40,000 included ($0.60/1k after) or Business $200 for 400,000 ($0.40/1k after). Below ~40,000, Plunk PAYG can be cheaper than Lumail’s $20 floor. At Business-scale included volume, Lumail’s published buckets undercut $0.001. Self-hosted Plunk has no Plunk send fee. Check both pricing pages.

What is the main difference between Lumail and Plunk?

Operating model. Plunk is developer-first open source: REST/SMTP, graph workflows, campaigns, inbound, self-host or $0.001 cloud. Lumail is an agent-operated newsletter platform: MCP, ChatGPT plugin, CLI, SDK, capture pages, and SMTP at smtp.lumail.io:587 in the same org. Plunk has no official MCP catalog. Lumail is not self-hostable and has no inbound-email product listed like Plunk’s MX catch-all.

Can I migrate from Plunk to Lumail?

Contacts can be exported from Plunk (CSV import exists on Plunk’s API; export path is the dashboard, not fully documented as an API). Recreate segments, templates, campaigns, and workflow graphs in Lumail—the APIs differ (Plunk next-api.useplunk.com vs Lumail REST/MCP). Transactional /v1/send and SMTP clients must be re-pointed. There is no official Plunk-to-Lumail importer on either site. Plan a cutover of domains (DKIM/SPF) and suppressions, then verify with a small send.

Try the workflow that matters most

Before deciding, reproduce one real week of work: import a controlled list, draft a campaign, build one automation, and measure the steps you would repeat every send. Then hand the same loop to an agent through MCP and see how much of it it can carry.

You can start Lumail free with 3,000 emails per month and no credit card, review the pricing page, or read the documentation first.

Still evaluating? Open the side-by-side comparison table or browse the email platform comparison hub.