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 → | 0 | 2 |
| 1M–10M | 1st of 10 → | 7 | 7 |
From June 3rd to August 31st, Knock routed <1M messages through Mailtrap and 1M–10M through Resend. Mailtrap reported 2 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 June 3rd to August 31st. The top-line number is an average of these daily values: Mailtrap averaged 81ms compared to 90ms for Resend. Mailtrap's highest daily p50 was 211ms; Resend's was 106ms. 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 177ms compared to 145ms for Resend. The highest daily p90 was 2812ms for Mailtrap and 3588ms for Resend. Resend handles these slower requests 32ms 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 846ms at p99 while Resend reached 1279ms. The highest daily p99 was 44357ms for Mailtrap and 19930ms 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% |
|---|---|---|---|---|---|
| 0.01% | 2.86% | Jun 22 | 88 | 2 |
| 0.02% | 1.28% | Jul 1 | 74 | 9 |
Averaged across the date range, Mailtrap shows a 0.01% daily error rate compared to 0.02% for Resend. The highest single-day error rate was 2.86% for Mailtrap and 1.28% 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 Aug 1, 2026 — Resolved Aug 1, 2026
Pingdom says we are back online.
Recent Resend incidents
Recent status page incidents for Resend
Started Aug 20, 2026 — Resolved Aug 20, 2026
Status: Resolved We have resolved the underlying issue and service latency has been recovered. Affected components General API (Operational)
Started Aug 19, 2026 — Resolved Aug 19, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed. Affected components Webhooks (Operational)
Started Aug 16, 2026 — Resolved Aug 16, 2026
Status: Resolved API became unstable from 12:54 to 12:57 UTC, returning 5xx for approximately 7% of the requests. We have resolved the underlying issue and service has been resumed.
Started Aug 13, 2026 — Resolved Aug 13, 2026
Status: Resolved Between approximately 17:30 and 17:43 UTC, requests to add a new domain failed in the dashboard and through the public API (POST /domains). Verification of domains added during this window was also affected. The issue was identified and fixed, and domain creation has returned to normal. No domains were partially created: affected requests failed immediately, so retrying the domain creation will succeed. Email sending for existing domains was not affected. Affected components
Started Aug 9, 2026 — Resolved Aug 9, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed.
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
What is the difference between Mailtrap and Resend?
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.
Which is cheaper, Mailtrap or Resend?
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.
Which is faster, Mailtrap or Resend?
Based on real-world data from Knock, Mailtrap has a median API response time (p50) of 81ms compared to 90ms for Resend.
Which is more reliable, Mailtrap or Resend?
From June 3rd to August 31st, Mailtrap showed an error rate of 0.01% while Resend showed 0.02%. Both rates are within acceptable thresholds for production email delivery, and Knock automatically retries failed requests to minimize the impact of transient errors.
Which is more popular, Mailtrap or Resend?
On the Knock platform, Mailtrap handled <1M messages from June 3rd to August 31st compared to 1M–10M for Resend. Mailtrap volume has remained stable, while Resend volume has remained stable.
Can I use both Mailtrap and Resend together?
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.
What are the main pros and cons of Mailtrap vs Resend?
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.