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
Get this app — pick a BluixApps plan
Same catalog. Scaling tenant isolation, white-label and support tier.
| Tier | Tenants | Catalog | Support | White-label | Monthly | |
|---|---|---|---|---|---|---|
| Stacks | 1 | 19 curated stacks | Standard | — | $19/mo | DetailDeploy |
| Starter | 10 | Full catalog | Standard | +$15–25/mo | $49/mo | DetailDeploy |
| Pro | 25 | Full catalog | Priority bugfix | +$15–25/mo | $149/mo | DetailDeploy |
| Growth | 100 | Full catalog | Priority bugfix | +$15–25/mo | $349/mo | DetailDeploy |
| Scale | 500 | Full catalog | 7-day window | +$15–25/mo | $799/mo | DetailDeploy |
| Enterprise | Unlimited | Full catalog | Priority 7-day | Bundled | $1,499/mo | DetailDeploy |