Postal

Self-hosted mail delivery platform for application email

oss-osi-approved stub guide

Overview

Postal is a mail delivery platform for sending application email. Teams with strong ops skills use it instead of commercial ESP—at significant reputation risk if misconfigured.

At a glance

Field	Value
Categories	`email-marketing`, `developer-platform`
Deployment	`self-hosted`
License class	oss-osi-approved (`MIT`)
Cost model	`free-self-hosted`
Implementation difficulty	`expert`
Maintenance burden	`medium`
Maturity	`stable`
Verification	`partially-verified` (2026-07-17)

Cost reality

Free software; warm-up, IPs, and compliance work dominate cost.

Pricing and free-tier limits change frequently; re-check official pricing before budget decisions.

Tasks reduced or augmented

Software does not replace community or ops staff. It may reduce or augment:

Transactional email sending
Message tracking

Human oversight still needed

IP reputation
Bounce handling
Legal sending requirements

Data held

messages
server endpoints
webhooks
Personal data: yes
Payment data: no / not primary

Risks

Area	Notes
Vendor lock-in	Evaluate export formats and API completeness before deep customization.
Security	Apply updates promptly; restrict admin access; enable TLS.
Compliance	Operator remains responsible for privacy and local regulatory obligations.
Licensing	Confirm license fits commercial coworking use.
Operational	Plan backups, monitoring, and a restore drill before production use.

Coworking fit

Roles: technical-operator

Workflows: marketing-campaigns, member-onboarding

Problems: self-host-for-data-control, reduce-software-cost

Smallest useful experiment

Only after SPF/DKIM/DMARC mastery: send transactional mail for one staging app to internal addresses.

Typical time to first value: 1–3 days

Implementation guide

See the human-written implementation guide.

Verification

Status: partially-verified
Last reviewed: 2026-07-17
Sources:

Seed entry compiled from official project sites and repositories. Re-verify pricing, license text, and feature claims before production decisions. Star counts and free-tier numeric limits intentionally omitted unless verified at review time.