Send better email. Own the whole stack.
Owlat is an open-source, self-hosted email platform. Campaigns, automations, transactional sends, and audience ops — with its own MTA and deliverability tooling built in.
Desktop app for macOS, Windows and Linux — in alpha, like the rest of Owlat.
Built on open standards
One calm surface for
all of your email
The mail client, campaign reports, and deliverability tooling live in one light workspace — no tab juggling between tools.
Product previews: the Postbox mail client with a folder rail, thread list and reading pane; a campaign report with send, open and click statistics; and the deliverability dashboard showing SPF, DKIM and DMARC checks, the own-MTA sending share, and seed placement results.
How mail moves
From queue to inbox — and back. Delivery signals feed the ramp controller, so your sending reputation grows instead of guessing.
Diagram of Owlat's mail flow: campaigns, automations and API sends queue on the built-in Owlat MTA; messages pass an authentication gate applying DKIM, SPF and DMARC, then reach recipient inboxes. Bounce, engagement and placement signals flow back into a ramp controller, which adjusts the MTA's sending share and pacing — a continuous deliverability feedback loop.
Everything you need
to ship email
From builder to inbox, every tool in one platform.
Block-based email editor
17 drag-and-drop block types with inline text editing. Build with text, images, buttons, columns, tables, carousels, and more. Save blocks to your library, manage translations per language, and preview across devices in real time.
Audience engine
Store contacts with custom properties, organize into topics with double opt-in, build dynamic segments with filters, import via CSV, and capture leads with embeddable forms.
Campaigns + A/B testing
Schedule sends for optimal timing, test subject lines and content variants side by side, then track opens, clicks, and engagement as results come in.
Automations
Build trigger-based flows for onboarding, re-engagement, and lifecycle messaging. Add delays, conditions, and branching logic — no code required.
Transactional delivery
Send password resets, order confirmations, and receipts via API. Reference templates by slug or ID, inject dynamic data variables, and fall back to the default language automatically.
Deliverability
Verify your sending domain with guided DNS setup for SPF, DKIM, and DMARC. Manage blocklists, automatically include one-click unsubscribe headers, and stream delivery events via webhooks for full visibility.
Ship with the SDK,
or stay in the dashboard
Send transactional emails, manage contacts, trigger automations, and track delivery with a single API call. Use the TypeScript SDK for type-safe integrations or hit the REST API directly from any language.
import { Owlat } from '@owlat/sdk-js'
const owlat = new Owlat('lm_live_...')
// Send a transactional email
await owlat.transactional.send({
email: 'mira@acme.io',
slug: 'welcome-email',
dataVariables: { firstName: 'Mira' }
})
// Create a contact and add to a list
const contact = await owlat.contacts.create({
email: 'mira@acme.io',
firstName: 'Mira'
})
await owlat.lists.addContact({
listId: 'list_abc123',
email: 'mira@acme.io'
})Built in the open,
owned by you
Inspect every line, self-host on your terms, and contribute to the platform you rely on. Fork it, extend it, migrate away — you always own your email stack.
Free forever. Your infrastructure.
Open-source under Apache 2.0. Hosted cloud is coming later — self-host today and own your data.
Available today
Self-Host
Run on your own VPS. No limits. No billing.
Free forever
- All features — no gated tiers
- Unlimited sends
- Unlimited team members
- Unlimited contacts
- In-app updates (one-click)
- Apache 2.0 licensed
Coming soon
Hosted Cloud
We run it for you. Launch in Q3.
€— /mo
- Managed infrastructure
- Dedicated IPs & warmup
- Automatic updates & backups
Resource requirements
What your VPS needs to run Owlat.
| Minimum | Recommended | |
|---|---|---|
| RAM | 4 GB | 8 GB |
| Disk | 20 GB | 40 GB |
| CPU | 2 vCPU | 4 vCPU |
| Domain + DNS | Required | Required |
Start sending better email
Every feature is included from the start — no feature gates, no plan upgrades.
Apache 2.0Free to self-hostNo per-contact pricing10-minute install