Postmark API
performance benchmarks
Browse Postmark's observed email API response time, error rates, and incident history over the last 90 days.
Live performance metrics
Real-world performance data from messages sent through Knock.
| Message volume | Growth | Status page updates (30d) | Status page updates (90d) |
|---|---|---|---|
10M–25M | 4th of 10 ↓ | 0 | 0 |
From August 13th to November 11th, Knock routed 10M–25M messages through Postmark. For adoption, Postmark ranks 4th of 10 providers based on new channel connections, with adoption slowing over the period. Postmark reported no status page incidents over the last 90 days.
Postmark response time
Response time measures how long Postmark takes to accept an API request from Knock, including connection overhead and any automatic retries. Lower values mean faster message hand-off.
| Median (p50) | p90 | p95 | p99 |
|---|---|---|---|
59ms | 83ms | 106ms | 241ms |
From August 13th to November 11th, Postmark averaged a daily median response time (p50) of 59ms across all days in the range, meaning half of all requests on a typical day complete in under 59ms. The 99th percentile averaged 241ms, with a peak daily p99 of 1224ms. This is slightly higher than some providers, which may reflect additional processing Postmark performs on message acceptance.
Postmark error rate
Error rate tracks the ratio of 5xx responses and timeouts to total requests. Knock automatically retries failed requests, so transient provider errors rarely affect end-user delivery.
| Avg. daily error rate | Highest daily rate | Peak error date | Zero-error days | Days above 0.01% |
|---|---|---|---|---|
0.00% | 0.01% | Aug 30 | 89 | 0 |
From August 13th to November 11th, Postmark averaged a 0.00% daily error rate for 5xx responses and timeouts, with the highest single-day error rate reaching 0.01%. This is one of the lowest error rates among providers on Knock, indicating strong reliability and consistent uptime. Knock automatically retries failed requests, so transient provider errors rarely affect end-user delivery.
About these metrics: Data represents messages sent through Knock to Postmark during the specified period. Response time measures time from Knock to provider acceptance. Error rate includes only provider 5xx responses and timeouts.
Recent Postmark incidents
Recent status page incidents for Postmark
No incidents reported in the last 90 days
Postmark pricing calculator
See how Postmark's monthly cost changes as your email volume grows.
Compare Postmark with other providers
See how Postmark compares on performance, reliability, and pricing.
About Postmark
Postmark is a transactional email service focused on fast, reliable delivery with transparent pricing.
Pros
- Excellent deliverability with separate infrastructure for transactional and bulk messages
- Publishes time-to-inbox data across major email providers for transparency
- Great documentation with official and community-supported SDKs for all major languages
- 45-day message and log retention on all plans
Cons
- No visual drag-and-drop email editor
- Less suited for high-volume marketing email
- Smaller feature set compared to all-in-one platforms
Frequently asked questions
Postmark is an email service provider commonly used for transactional email, password resets, welcome emails. Postmark is a transactional email service focused on fast, reliable delivery with transparent pricing.
Free tier includes 100 emails per month. Paid plans start at $15/month for 10,000 emails on Basic, $16.50/month on Pro, and $18/month on Platform. Published pricing ends at 1.5 million emails per month. Postmark offers a free tier with up to 100 emails, with a hard sending limit on that plan.
Based on real-world data from messages sent through Knock, Postmark accepts API requests with a median response time of 59ms (p50) and 241ms at the 99th percentile.
From August 13th to November 11th, Postmark showed an error rate of 0.00% for 5xx responses and timeouts across 10M–25M messages sent through Knock. Knock automatically retries failed requests, so transient provider errors rarely affect end-user delivery.
Key strengths include excellent deliverability with separate infrastructure for transactional and bulk messages and publishes time-to-inbox data across major email providers for transparency. On the other hand, no visual drag-and-drop email editor and less suited for high-volume marketing email.
Yes. Knock has a native Postmark integration that enables you to send email notifications through Postmark as part of a cross-channel workflow. You can combine Postmark with other channels like in-app feeds, push, SMS, and Slack from a single API call.