Built in Denmark · Hosted in Finland
The EU-hosted email API
PostStack sends transactional and marketing email from the EU: REST API, SMTP relay, SDKs, an MCP server for AI agents, and hosted mailboxes. Up to 72% cheaper than Resend, SendGrid, and Postmark.
3,000 emails a month free · No credit card required
› "send ada@lovelace.io a personalised welcome email"
● get_contact_by_email
email: "ada@lovelace.io"
→ con_4tq9… · Ada Lovelace · referrer=hacker-news
● render_template
template_id: "tpl_9fq2…"
variables: { first_name: "Ada", referrer: "Hacker News" }
→ subject "Welcome aboard, Ada" · 0 missing variables
● lint_email rendered subject + html
→ score 0.80 → no_action
● send_email
from: "hello@yourdomain.com"
to: ["ada@lovelace.io"]
template_id: "tpl_9fq2…", variables: {…}
✓ Email queued — em_7kf2x9…A complete email platform for European teams
REST API, SMTP relay, templates, contacts, broadcasts, analytics, and mailbox hosting. All on EU infrastructure, all from one provider.
SDKs and API
One POST request sends an email. Official TypeScript, Python, and Go SDKs. MCP server for Claude, Cursor, and other AI assistants. Dashboard for non-developers on your team.
Deliverability
Add a domain and get the exact SPF, DKIM, and DMARC records to publish, or connect Cloudflare and PostStack writes them for you. Bounces and complaints are suppressed automatically. RFC 8058 one-click unsubscribe is built in.
Analytics
Opens, clicks, deliveries, bounces, and complaints tracked in real time. Live dashboard, exportable reports, and webhook events for every change.
Templates
{{variable}} placeholders with if/unless blocks, in your own HTML (React Email output included) or the visual editor. Preview, publish, and version templates without redeploying your app.
Contacts and broadcasts
Import contacts and segment them by custom properties or engagement, like "opened 3+ emails in 30 days". Schedule broadcasts, A/B test them, and resend to non-openers in one click.
Mailboxes and webmail
Full email hosting with a built-in webmail client. Create mailboxes on your own domain, read and send from the dashboard, or connect any email client over IMAP or POP3. €1/mo per mailbox on any paid plan.
SMTP relay
Standard SMTP that works with any client: WordPress, Laravel, Rails, nodemailer, or your AI agent. Use your API key as the password.
Webhooks
HMAC-signed notifications for every email event. Deliveries, bounces, opens, clicks, and complaints delivered to your endpoint with automatic retries.
European infrastructure
Hetzner data centre in Helsinki, Finland. GDPR compliant by default. Your email data stays inside the EU and is not subject to the US CLOUD Act.
Start sending in your stack
Copy-paste quickstarts for the language and framework you already use.
Start free. Paid plans from €5/mo.
3,000 emails free every month, forever. No credit card required, no contract, cancel anytime.
Free
For side projects and testing
- 3,000 emails/month
- 1 domain
- 5 API keys
- 14-day log retention
- Webhooks
Starter
For indie makers and small SaaS
- 10,000 emails/month
- 3 domains
- 10 API keys
- 14-day log retention
- Webhooks
Pro
For startups and growing products
- 50,000 emails/month
- 10 domains
- 50 API keys
- 30-day log retention
- Webhooks
Scale
Higher volume, domains & retention
- 100,000 emails/month
- 1,000 domains
- 1000 API keys
- 90-day log retention
- Webhooks
Add hosted mailboxes to any paid plan for €1/mo each (includes 1 GB; extra storage €1/GB/mo) — add as many as you need, anytime from the dashboard. Prices exclude VAT, added at checkout based on your location.
Enterprise
Custom volumes, dedicated infrastructure, SLA, and priority support for high-scale senders.
- Unlimited emails/month
- Unlimited domains
- Unlimited API keys
- Unlimited log retention
- Priority support & SLA
- Custom contracts
Coming from another email API?
See where PostStack fits versus the provider you're on today — pricing, features, and migration paths laid out side-by-side.
Frequently asked questions
Common questions about PostStack, EU data residency, pricing, and migration.
Where is PostStack hosted?
In Helsinki, Finland (Hetzner hel1). All email content, recipient data and message metadata stay inside the EU and are not subject to the US CLOUD Act. PostStack is a Danish company. The only sub-processor outside the EU is GitHub, and only for users who choose "Sign in with GitHub"; the full list is at /sub-processors.
Do you offer a free tier?
3,000 emails every month, free forever. No credit card required to sign up. You can send from a verified domain as soon as DKIM and SPF records propagate.
Can I migrate from Resend, SendGrid, or Postmark?
Yes. Each provider has a step-by-step migration guide at /migrate/resend, /migrate/sendgrid, and /migrate/postmark. Coming from Resend it is mostly a rename: the same Bearer-token auth and the same JSON fields (from, to, subject, html). SendGrid and Postmark use different field names, and each guide maps them one by one. Most teams migrate in under an hour.
Is PostStack GDPR compliant?
Yes. PostStack runs only on EU infrastructure, keeps all email content, recipient data and message metadata inside the EU, and provides a Data Processing Agreement at /dpa that you can sign in the dashboard on any plan (counter-signed copy on request). We publish our sub-processors and security posture at /trust.
Do you support SMTP as well as the REST API?
Yes. The SMTP relay accepts WordPress, Laravel, Rails, nodemailer, and any standards-compliant SMTP client. Use your API key as the SMTP password. Full setup is documented at /docs/smtp.
How does PostStack compare to Resend on price?
Up to 72% cheaper at the entry tier: Starter is €5/month for 10,000 emails, where Resend starts at $20/month. At 500,000 to 1,000,000 emails a month PostStack is roughly 55–60% cheaper; between 50,000 and 100,000 the two are much closer. The full side-by-side comparison is at /pricing/compare.
Do you support MCP, Claude, and AI agents?
Yes. PostStack ships a native MCP server for Claude, Cursor, and other AI assistants with 100+ tools, so agents can send email, lint drafts for spam, manage contacts, and find and re-engage non-clickers on a broadcast as tool calls. Setup guide at /docs/mcp.
Can I host my own mailboxes on my domain?
Yes, on any paid plan. Each mailbox is €1/month with 1 GB of storage included (extra storage €1/GB/month), with IMAP, POP3, and a browser webmail client. Create mailboxes on your own domain and use them alongside the transactional API.
What about bounces, complaints, and suppressions?
Bounces and complaints are handled automatically, with suppressions maintained per account. RFC 8058 one-click unsubscribe is built in for Gmail and Yahoo compliance.
Send your first email in minutes
3,000 emails a month free, forever. No credit card required. EU-hosted from day one.