Postal

App in the BluixApps catalog

What it is

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.

What it's for

  • Transactional email — password resets, order confirmations, notifications
  • 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

  • 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

Why teams pick Postal over 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

  • 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

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

Tips & operations

  • Reverse DNS + SPF + DKIM + DMARC — non-negotiable for delivery
  • Warm up new IPs — gradual ramp from low volume; cold IPs get spam-flagged
  • Monitor bounce rate — >5% = sender reputation issue; investigate
  • Suppression list discipline — Postal manages this automatically; trust it
  • Persistent MySQL + RabbitMQ — both essential
  • Multiple sender IPs — for high volume, multi-IP rotation helps deliverability

What we ship in BluixApps

  • 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
Read this app's deep dive on bluix.app ↗

Get this app — pick a BluixApps plan

Same catalog. Scaling tenant isolation, white-label and support tier.

TierTenantsCatalogSupportWhite-labelMonthly
Stacks119 curated stacksStandard$19/moDetailDeploy
Starter10Full catalogStandard+$15–25/mo$49/moDetailDeploy
Pro25Full catalogPriority bugfix+$15–25/mo$149/moDetailDeploy
Growth100Full catalogPriority bugfix+$15–25/mo$349/moDetailDeploy
Scale500Full catalog7-day window+$15–25/mo$799/moDetailDeploy
EnterpriseUnlimitedFull catalogPriority 7-dayBundled$1,499/moDetailDeploy

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