More SMTP traffic raises app, database and queue activity.
High-volume transactional senders.Postal Hardware Requirements: RAM, CPU, MariaDB & Mail Storage
Plan Postal hardware using its official 4 GB RAM, 2-core and 25 GB minimum, plus MariaDB, SMTP port 25, DNS and ZimaOS deployment guidance.
Postal requirements at a glance
Postal is a mail-delivery platform where IP reputation, DNS and outbound SMTP connectivity matter as much as local compute.
- RAM minimum
- Official minimum: at least 4 GB RAM.
- CPU minimum
- Official minimum: at least 2 CPU cores.
- Storage minimum
- Official minimum: at least 25 GB, with more based on message/data retention.
- Host recommendation
- Postal strongly recommends its own dedicated server running no other software.
- Database
- MariaDB 10.6 or newer is required; Postal explicitly does not support MySQL as a substitute.
- Networking
- Outbound port 25 must not be blocked, and correct mail-server DNS configuration is required.
From official requirements to the right setup
Postal should be planned as dedicated mail infrastructure rather than a normal shared web app.
-
Official requirements
Reserve at least 4 GB RAM, 2 CPU cores and 25 GB disk, and prefer a dedicated host as Postal recommends.
-
Confirm your needs
Provide MariaDB 10.6+ and size innodb_log_file_size to at least ten times the largest email message size you plan to accept/send.
-
Leave room to grow
Verify outbound SMTP port 25, public IP reputation, A/AAAA/MX and other required mail DNS records before relying on the installation.
-
Run it on ZimaOS
On ZimaOS, use Install Custom App only if you accept a co-hosted Docker topology; for production mail delivery, keep Postal isolated from unrelated apps as closely as possible.
Check every playback client
- 4 GB+ RAM
- 2+ CPU cores
- 25 GB+ disk
- MariaDB 10.6+
- Outbound port 25
- Public IP reputation
- Mail DNS records
- Backup retention
Official minimum requirements
Postal's current prerequisite page provides explicit minimum server specifications and a dedicated-host recommendation.
The 4-GB/2-core/25-GB values are the official minimum. Mail delivery also depends on dedicated-host hygiene, MariaDB, port 25 and DNS/reputation, which hardware alone cannot solve.
| Requirement | Official minimum | What this supports |
|---|---|---|
| RAM minimum | 4 GB | Current official minimum. |
| CPU minimum | 2 CPU cores | Current official minimum. |
| Disk minimum | 25 GB | Current official minimum; scale for use case. |
| Host topology | Dedicated server strongly recommended | Postal recommends running no other software. |
| Database | MariaDB 10.6+ | MySQL is explicitly unsupported as a replacement. |
| Outbound SMTP | Port 25 must be available | Provider blocking can prevent mail delivery. |
When to upgrade your hardware
Postal should scale when message throughput, MariaDB data or retention outgrows the minimum server profile.
Message throughput increases
MariaDB data and message retention grow
Mail reputation/network constraints become the bottleneck
Postal provisions message databases and can accumulate significant history.
Long-retention or high-volume installations.A larger server does not fix blocked port 25 or poor IP reputation.
Any production sender.Plan hardware growth with confidence
Scale Postal around dedicated resources, MariaDB performance and mail-delivery networking.
Use SSD-backed MariaDB storage
Low-latency durable database storage helps message and configuration activity.
Use SATA/NVMe with Zima hardware.Use 8 GB+ for comfortable dedicated small deployments
Provides margin above the 4 GB minimum for MariaDB and Postal processes.
ZimaBoard 2 832 if Postal is effectively isolated from unrelated apps.Use 16 GB for higher throughput or more retention
Extra memory benefits MariaDB and the broader Postal stack.
ZimaBoard 2 1664.Use ZimaCube only when storage/network duties justify it
Larger retention and broader storage may justify ZimaCube, but mail reputation remains independent of hardware.
ZimaCube 2 Pro.Can it run on ZimaOS?
No public official ZimaOS one-click Postal App Store page was verified for this guide. Postal can run in containers, but upstream strongly recommends a dedicated server, so a shared ZimaOS host is not the ideal production topology.
Custom install Postal in ZimaOS
Use Install Custom App only when you understand Postal's dedicated-host recommendation, persist MariaDB/Postal data, and verify outbound port 25 plus mail DNS before production use.
Custom install Postal in the ZimaOS app โFollow Postal's official prerequisites
Current docs require at least 4 GB RAM, 2 CPU cores, 25 GB disk and MariaDB 10.6+, and strongly recommend a dedicated server.
Review Postal prerequisites โConfigure Postal DNS correctly
Postal requires appropriate DNS for its management/API/SMTP hostnames and mail domains.
Review Postal DNS configuration โChoose Zima hardware for Postal
Postal's minimum fits ZimaBoard 2, but production suitability depends heavily on isolation, outbound SMTP access and IP/DNS reputation.
Is this a small isolated Postal server or a higher-volume mail-delivery workload?
Small isolated Postal deployment
Use ZimaBoard 2 832 only when it is effectively dedicated to Postal and its database.
- Minimum-class fitZimaBoard 2 832
- More database headroomZimaBoard 2 1664
Higher throughput or larger data retention
Use stronger CPU/storage while keeping Postal isolated from unrelated services.
- Higher-headroom platformZimaCube 2 Pro
These are hardware mappings only; they do not guarantee email deliverability or sender reputation.
| Zima hardware | Best for | Example workload | Core configuration | Recommended boundary | Next step |
|---|---|---|---|---|---|
| ZimaBoard 2 832 | Small isolated Postal deployments. | Postal, MariaDB and modest mail volume. |
|
Meets the 4-GB/2-core/25-GB minimum, but Postal recommends a dedicated server and outbound port 25 must work. | Get Now |
| ZimaBoard 2 1664 | Postal with more MariaDB cache and retention. | Higher mail/database activity with greater memory headroom. |
|
Still avoid unrelated co-hosted services for a production sender. | Get Now |
| ZimaCube 2 Pro | Higher-volume Postal and larger retention. | Stronger CPU, 16 GB RAM, larger SSD/storage options and faster local networking. |
|
Hardware cannot fix blocked SMTP, poor IP reputation or DNS problems. | Get Now |
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Highlights from trusted reviewers worldwide.
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Frequently asked questions
These answers cover Postal RAM, CPU, storage, MariaDB, port 25, DNS and ZimaOS deployment.
How much RAM does Postal need?
Postal's official minimum is 4 GB RAM.
How many CPU cores does Postal need?
Postal's official minimum is 2 CPU cores.
How much storage does Postal need?
The official minimum is 25 GB, with additional space based on your message and retention workload.
Which database does Postal require?
Postal requires MariaDB 10.6 or newer and explicitly does not support MySQL as a replacement.
Does Postal require port 25?
Yes for normal SMTP delivery; the official prerequisites warn that providers often block outbound port 25.
Should Postal share a server with other apps?
Postal strongly recommends a dedicated server running no other software.
Can ZimaBoard 2 run Postal?
Yes from a hardware perspective, but production deployment should respect Postal's dedicated-host and networking requirements.
Does Postal need a GPU?
No dedicated GPU is required.
What sources informed this Postal hardware guide?
Current Postal prerequisites, container and DNS documentation plus current Zima product pages.
