Lumail vs Postmark
Lumail
Postmark
Transactional email API and SMTP service
Lumail and Postmark pricing and feature comparison
Free emails / month
Lumail
3,000
Postmark
100
Unlimited subscribers · $0
$0
Paid entry
$20/month, 40,000 included, then $0.60/1,000
$15/month for 10,000 emails
Pricing basis
Unlimited subscribers; pricing follows email volume
Monthly email volume, not subscribers; extra emails billed per 1,000
Automation
Graph workflows with triggers, branches, goals, exits, and A/B paths
No journeys or drip builder; sequences live in your app
AI and developer access
ChatGPT OAuth, MCP, skills, CLI, SDK, REST API, and visual editor
Local MCP server with 24 tools, agent skills, and a CLI
Transactional email
Included through API, SMTP, SDK, CLI, and agent tools
Core product, via REST API or SMTP
Publishing surface
Capture pages and custom web domains; not a general website builder
Server-side templates and broadcast streams; no newsletter editor
Choose Lumail if…
- You want campaigns, workflows, subscribers, and transactional email in one account
- You need a visual editor and workflows instead of sending newsletters from code
- You want 3,000 free emails a month instead of 100
Choose Postmark if…
- Transactional email from code is all you need
- Your lists already live in your app and you only need a sending API
- You need inbound email parsing or dedicated IPs at high volume
Weighing more than two tools? Read the best Postmark alternatives guide, which compares the options side by side.
Where Postmark is strong
A real alternative, not a straw man.
Postmark is a developer email service for transactional and broadcast app email via API and SMTP, with separate streams so their sending reputations never mix. People pick Postmark when they need product engineering teams that need reliable transactional email from code.
- Separate infrastructure for transactional and broadcast email
- API, SMTP, SDKs, webhooks, templates, and 45 days of message history
- 24-tool MCP server, agent skills, and CLI
Don't trust the table. Run one journey.
Checklists lie by flattening the work. Build one real path: a trigger, a wait, a branch, a goal, an exit. Then open one subscriber and see what actually happened. That tells you more than any feature row.
- 1. Import a small, consented sample. Not the whole list.
- 2. Recreate one campaign and the audience it actually hits.
- 3. Publish one automation with a goal you can measure.
- 4. Fire a test and read every event on one person.
- 5. Compare the weekly work, not the setup afternoon.
Try it on a real send
Keep the whole list. Pay when you send.
3,000 emails free, no card. Rebuild one campaign, one workflow, and one transactional message before you move anyone. If it feels worse than Postmark, stay.
The questions people actually ask
Is Lumail cheaper than Postmark?
Sometimes. Lumail is $0 for 3,000 emails, then $20 for 40,000. Postmark's number only makes sense after you know what they cap: contacts, seats, a daily send limit, or a feature they hide behind a paid plan. Read the honest take above, then price a normal month and a launch month on both pages.
What is the main difference between Lumail and Postmark?
Choose Postmark when you need fast, reliable transactional email sent from code. Choose Lumail when newsletters, workflows, subscribers, and transactional email should live in one place agents can operate.
Can I migrate from Postmark to Lumail?
Yes. Don't move the whole list on day one. Export a small consented sample, rebuild one campaign and one automation, authenticate your domain, then watch one subscriber go through the run. If that feels right, move the rest.