Mailtrap vs Resend
Compare Mailtrap and Resend based on observed API performance, features, and pricing
Live performance comparison
Real-world performance data from messages sent through Knock
| Provider | Message volume | Growth | Status page updates (30d) | Status page updates (90d) |
|---|---|---|---|---|
| <1M | 9th of 10 ↓ | 1 | 5 |
| 1M–10M | 1st of 10 → | 7 | 7 |
From July 24th to October 22nd, Knock routed <1M messages through Mailtrap and 1M–10M through Resend. Mailtrap reported 5 status page updates over the last 90 days, while Resend reported 7.
Response time
Response time measures how long each provider takes to accept an API request from Knock, including connection overhead and any automatic retries. Lower values mean faster message hand-off.
The chart above shows each provider's daily median response time (p50) from July 24th to October 22nd. The top-line number is an average of these daily values: Mailtrap averaged 81ms compared to 83ms for Resend. Mailtrap's highest daily p50 was 218ms; Resend's was 96ms. Both providers deliver comparable response times for the typical request.
The 90th percentile (p90) captures the slowest 10% of requests, revealing how each provider handles moderate stress. Averaged across all days, Mailtrap has a p90 of 163ms compared to 123ms for Resend. The highest daily p90 was 907ms for Mailtrap and 3594ms for Resend. Resend handles these slower requests 40ms faster, suggesting more consistent performance across the board.
The 99th percentile (p99) represents the long tail — the slowest 1% of requests. Averaged across all days, Mailtrap reached 755ms at p99 while Resend reached 944ms. The highest daily p99 was 1675ms for Mailtrap and 11263ms for Resend, indicating the worst-case response time during spikes or provider-side congestion. Mailtrap shows a tighter tail, which may matter for time-sensitive notifications like one-time passwords or real-time alerts where even rare delays can impact user experience.
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.
| Provider | Avg. daily error rate | Highest daily rate | Peak error date | Zero-error days | Days above 0.01% |
|---|---|---|---|---|---|
| 0.00% | 0.07% | Aug 1 | 90 | 1 |
| 0.00% | 0.09% | Oct 1 | 82 | 6 |
Averaged across the date range, Mailtrap shows a 0.00% daily error rate compared to 0.00% for Resend. The highest single-day error rate was 0.07% for Mailtrap This peak coincided with a major incident reported on Mailtrap's status page (Sending Services Downtime). and 0.09% for Resend. Both providers show similar reliability levels, with error rates well within acceptable thresholds. Knock automatically retries failed requests to both providers, minimizing the impact of transient errors on end-user delivery.
About these metrics: Data represents messages sent through Knock during the specified period. Response time measures time from Knock to provider acceptance. Error rate includes only provider 5xx responses and timeouts.
Recent Mailtrap incidents
Recent status page incidents for Mailtrap
Started Oct 8, 2026 — Resolved Oct 8, 2026
The maintenance is now complete. Thanks for your patience.
Started Aug 1, 2026 — Resolved Aug 1, 2026
Pingdom says we are back online.
Recent Resend incidents
Recent status page incidents for Resend
Started Oct 10, 2026 — Resolved Oct 10, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed. Affected components Dashboard (Operational) General API (Operational) Webhooks (Operational)
Started Oct 9, 2026 — Resolved Oct 9, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed. Affected components Webhooks (Operational) Dashboard (Operational) General API (Operational)
Started Oct 1, 2026 — Resolved Oct 1, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed Affected components General API (Operational)
Ongoing since Oct 1, 2026
Status: Complete All systems are now fully operational Affected components Dashboard (Operational) Website (Operational)
Started Sep 26, 2026 — Resolved Sep 26, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed. Affected components Webhooks (Operational)
Pros and cons
Mailtrap
Resend
Pros
- Strong deliverability with dedicated IPs, auto warmup, and automatic authentication
- Great developer experience with comprehensive docs and MCP support for IDEs
- Combined testing sandbox and production sending in one platform
- Trusted by PayPal, Atlassian, Adobe, and Yelp
Pros
- Beautiful documentation with attention to detail and great developer experience
- Created and maintain React Email, the go-to framework for building email templates in React
- Minimalist, developer-optimized platform that avoids bloat with a focused UI
- Transparent observability with real-time visibility into sends, failures, and engagement
Cons
- Native integration ecosystem is smaller than established competitors
- Lower sending limits on free tier compared to some providers
- No rate limits by default, which may require custom throttling configuration
Cons
- Newer and less battle-tested compared to incumbents like Mailgun or SendGrid
- Fewer enterprise features than established providers
- Limited marketing email capabilities
Frequently asked questions
Mailtrap is an email platform combining safe testing and sandbox environments with production sending capabilities. Resend is a modern email API built for developers, with React Email support and a focus on simplicity. Mailtrap is best suited for email testing + qa, while Resend is geared toward developer-first, react teams.
Free tier includes 4,000 emails per month (150/day limit). Paid plans start at $15/month for 10,000 emails with overages at $1.00/1K. Free tier includes 3,000 emails per month and 100 emails per day. Paid plans start at $20/month for 50,000 emails with overages at $0.90/1K on Pro, scaling down to $0.46/1K on Scale 2.5M. The best value depends on your sending volume. Use the pricing calculator above to compare costs at your expected volume.
Based on real-world data from Knock, Mailtrap has a median API response time (p50) of 81ms compared to 83ms for Resend.
From July 24th to October 22nd, Mailtrap showed an error rate of 0.00% while Resend showed 0.00%. Both rates are within acceptable thresholds for production email delivery, and Knock automatically retries failed requests to minimize the impact of transient errors.
On the Knock platform, Mailtrap handled <1M messages from July 24th to October 22nd compared to 1M–10M for Resend. Mailtrap is currently seeing declining volume, while Resend volume has remained stable.
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use Mailtrap and Resend side by side, route traffic between them, or migrate from one to the other without changing your application code.
Mailtrap strengths include strong deliverability with dedicated ips, auto warmup, and automatic authentication and great developer experience with comprehensive docs and mcp support for ides. Resend strengths include beautiful documentation with attention to detail and great developer experience and created and maintain react email, the go-to framework for building email templates in react. On the other hand, Mailtrap drawbacks include native integration ecosystem is smaller than established competitors, while Resend drawbacks include newer and less battle-tested compared to incumbents like mailgun or sendgrid.
Use either provider with Knock
Knock enables you to integrate Mailtrap, Resend, or any combination of email providers into a single notification workflow. Manage templates, orchestrate cross-channel delivery, and switch providers without changing your code.