Transactional email
password resets, order confirmations, notifications
// official site: postalserver.io ↗
MAIL · PRO TIER
Postalpro
Postal is a self-hosted SMTP relay / mail platform designed specifically for sending transactional and marketing email at scale — bounce handling, click tracking, webhooks, multi-tenant. Where Mailcow targets full mail server (inbox + outbox), Postal targets outbound-only programmatic email infrastructure.
// What it is
A closer look.
Postal is a self-hosted SMTP relay / mail platform designed specifically for sending transactional and marketing email at scale — bounce handling, click tracking, webhooks, multi-tenant. Where Mailcow targets full mail server (inbox + outbox), Postal targets outbound-only programmatic email infrastructure.
For SaaS founders who want to run their own SendGrid / Mailgun, Postal is the open-source answer.
// Use cases
What it's for.
Concrete scenarios where teams pick Postal over the SaaS alternative.
Marketing email at scale
bulk campaigns with tracking
API-driven email
REST + SMTP API for app integration
Multi-tenant email
host email infrastructure for multiple clients
Bounce + complaint handling
process feedback loops automatically
// Who it's for
Built for these teams.
If your team profile matches one of these, Postal is a strong fit out of the box.
SaaS founders
wanting independence from SendGrid/Mailgun
Agencies
providing email-as-a-service to clients
High-volume senders
with predictable VPS cost vs metered SaaS billing
Privacy-bound orgs
keeping email infrastructure in-network
Email engineers
who want full control over delivery infrastructure
// Differentiators
Why teams pick Postal.
When evaluating self-hosted options for this category, here are the dimensions on which Postal consistently lands above the alternatives.
- ✓MIT license — fully open
- ✓Built for scale — Ruby/Go architecture handles millions of messages
- ✓Click tracking — built-in tracking pixels + link rewriting
- ✓Bounce processing — automatic suppression list management
- ✓Webhooks — event firing on delivery / bounce / open / click
- ✓Multi-organization — tenant isolation for agency use
// Integrations
Connects to.
The stack you'll plug Postal into — services, protocols, and adjacent apps in the BluixApps catalog.
◇
API
REST + SMTP API for application integration
◈
Webhooks
fire on every email event
◆
Auth
local + OAuth (GitHub, custom OIDC)
▣
Bounce handling
automatic suppression with feedback loop processing
▦
Click + open tracking
built-in with privacy-friendly opt-out
▩
Templates
basic templating; pair with external system for advanced
▼
Queue management
RabbitMQ-backed for async send
// Adoption & deployment
Notable users & community
- 7k+ GitHub stars
- Used by SaaS founders and agencies running their own email infrastructure
- Active GitHub Discussions community
- Backed by ATECH (UK) with sustainable maintenance
- Featured in SendGrid-alternative guides
What we ship
- Docker compose: Postal + MariaDB + RabbitMQ
- Pinned
ghcr.io/postalserver/postal:3.3(release-tagged) - HTTPS via Let's Encrypt
- Admin user via env config
- Persistent volumes for MariaDB + RabbitMQ
- DKIM signing configured per domain
- Backup hook covers MariaDB + config
// Tips & operations
Run it properly.
Operational guidance from running this in production — what to lock down, what surprises people.
// PERFORMANCE
Reverse DNS + SPF + DKIM + DMARC
non-negotiable for delivery
// SECURITY
Warm up new IPs
gradual ramp from low volume; cold IPs get spam-flagged
// OPERATIONS
Monitor bounce rate
>5% = sender reputation issue; investigate
// RELIABILITY
Suppression list discipline
Postal manages this automatically; trust it
// DEPLOYMENT
Persistent MySQL + RabbitMQ
both essential
// SCALING
Multiple sender IPs
for high volume, multi-IP rotation helps deliverability
4096
// min ram (MB)
20
// min disk (GB)
5000
// access port
http
// protocol
pro
// bluixapps tier
// Alternatives in Mail
Compare with
Project resources
Official sitepostalserver.io ↗