Developer platforms

Postmark

Email delivery with developer documentation and publicly reported service status.

Official documentation ↗Add to a comparison →

WHEN TO CONSIDER IT

Consider when you want developer documentation and a public delivery-status reference.

WHAT TO CHECK FIRST

Inbound processing needs Pro or Platform; overage sending cannot be hard-capped in the account.

Editorial interpretation of the sourced facts; not hands-on testing.

Pricing

Billing model: Monthly card billing; no annual plansSource ↗
Selected paid rateSelected plans, not equivalent baskets. USD unless stated; taxes, add-ons and regional terms may differ.: 10k/month: Basic USD 15; Pro USD 16.50; Platform USD 18Source ↗
Free tier / trial: Developer plan: 100 emails/monthSource ↗
Overage: Per 1,000 above allowance; Basic example USD 1.80. Exact rate depends on tier.Source ↗
Data / attachment charges: Not stated in reviewed docs
Review details
Reviewed pricing does not establish a separate data or attachment transfer rate. This is not confirmation that all such charges are zero.
Reviewed 2026-09-08
Reviewed source 1 ↗
What counts as an email: Statistics count each recipient separately; Messages API TotalCount instead counts one multi-recipient message.Source ↗
Credit expiry: Unused monthly email allocation does not roll over.Source ↗

Reliability

Official incident historyProvider-reported status, not independent monitoring or a live health indicator.: Official status pageOpen ↗
Contractual uptime SLAA service commitment, not observed uptime. Eligibility, exclusions and credit rules differ.: Not stated in reviewed docs
Review details
No email-specific numerical contractual uptime commitment was established in the reviewed materials.
Reviewed 2026-09-08
Reviewed source 1 ↗Reviewed source 2 ↗
Measured uptime: Not measured
Measured delivery latency: Not measured
Measured inbox placement: Not measured

Sending & features

HTTP API: AvailableSource ↗
SMTP relay: AvailableSource ↗
SDKs: TypeScript/Node.js, Python, Ruby/Rails, .NET, Java, PHPSource ↗
Templates / editor: Template sending APISource ↗
Webhooks: Delivery, bounce, open, click and inbound events documentedSource ↗
Inbound processing: Pro / Platform include inbound processingSource ↗
Campaigns / automation: Separate transactional and broadcast message streamsSource ↗
Analytics: Open and link trackingSource ↗

Operations & security

Suppression management: Bounces and complaints retained in stream suppression listsSource ↗
Daily / request limits: Paid sending continues beyond allowance; no user-set hard spending capSource ↗
Log / activity retention: 45 days by default; retention add-on: 7–365 daysSource ↗
Dedicated IP: USD 50/IP/month; at least 300,000 messages/monthSource ↗
Hosting / region notes: Primary infrastructure: Chicago-area Deft and AWSSource ↗
Sending domains: Basic 5; Pro 10; Platform unlimitedSource ↗
Sender authentication: DKIM; default SPF; custom Return-Path for DMARC alignmentSource ↗
SSO: Not stated in reviewed docs
Review details
External identity-provider SSO protocols and plan eligibility were not established for this product.
Reviewed 2026-09-08
Reviewed source 1 ↗Reviewed source 2 ↗
Support channels: Support contact form; published hours Monday–Friday, 3am–7pm EST.Source ↗
Setup requirements: Verify sender signature or domain, then configure authenticationSource ↗

Resources

Website: Official resourceOpen ↗
Documentation: Official resourceOpen ↗
Pricing page: Official resourceOpen ↗

Sources & review scope

Reviewed 2026-09-08. Values are taken from official materials; plan restrictions may apply. Delivery speed, observed uptime and inbox placement have not been independently measured.

Official references (15)