MailerSend vs Mailtrap
Compare MailerSend and Mailtrap 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 | 7th of 10 ↓ | 1 | 2 |
| <1M | 9th of 10 ↓ | 1 | 5 |
From July 24th to October 22nd, Knock routed <1M messages through MailerSend and <1M through Mailtrap. MailerSend reported 2 status page updates over the last 90 days, while Mailtrap reported 5.
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.
| Provider | Median (p50) | p90 | p95 | p99 |
|---|---|---|---|---|
| 167ms | 349ms | 450ms | 1052ms |
| 81ms | 163ms | 218ms | 755ms |
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: MailerSend averaged 167ms compared to 81ms for Mailtrap. MailerSend's highest daily p50 was 730ms; Mailtrap's was 218ms. Mailtrap is 86ms faster at the median, which can add up at high volumes.
The 90th percentile (p90) captures the slowest 10% of requests, revealing how each provider handles moderate stress. Averaged across all days, MailerSend has a p90 of 349ms compared to 163ms for Mailtrap. The highest daily p90 was 3166ms for MailerSend and 907ms for Mailtrap. Mailtrap handles these slower requests 186ms 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, MailerSend reached 1052ms at p99 while Mailtrap reached 755ms. The highest daily p99 was 43537ms for MailerSend and 1675ms for Mailtrap, 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% | 0.00% | Jul 24 | 91 | 0 |
| 0.00% | 0.07% | Aug 1 | 90 | 1 |
Averaged across the date range, MailerSend shows a 0.00% daily error rate compared to 0.00% for Mailtrap. The highest single-day error rate was 0.00% for MailerSend and 0.07% for Mailtrap This peak coincided with a major incident reported on Mailtrap's status page (Sending Services Downtime).. 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 MailerSend incidents
Recent status page incidents for MailerSend
Started Oct 11, 2026 — Resolved Oct 11, 2026
Status: Complete Maintenance has completed Affected components Delivery time (Operational) Email sending API (Operational) Email analytics (Operational) Deliverability rate (Operational) MailerSend APP (Operational) Bulk endpoint (Operational) SMTP (Operational) Email activity (Operational)
Started Sep 21, 2026 — Resolved Sep 21, 2026
Status: Complete Maintenance has completed Affected components Inbound routing (Operational) Bulk endpoint (Operational) SMTP (Operational) Delivery time (Operational) Email sending API (Operational)
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.
Pros and cons
MailerSend
Mailtrap
Pros
- Designed for both developers and business users with API and visual editor
- Modern, intuitive UI that is easier to navigate than older platforms
- Multi-channel support with native email and SMS transactional messaging
- Affordable Hobby plan at $7/month for 5,000 emails with low overage rates
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
Cons
- Available integrations with other tools are basic and limited
- Fewer advanced features than enterprise platforms
- Smaller ecosystem compared to established competitors
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
Frequently asked questions
Mailersend is an intuitive transactional email and SMS service by Mailgun, designed for growing businesses. Mailtrap is an email platform combining safe testing and sandbox environments with production sending capabilities. MailerSend is best suited for growing saas + e-commerce, while Mailtrap is geared toward email testing + qa.
Free tier includes 500 emails per month. Paid plans start at $7/month for 5,000 emails on the Hobby plan, with the Starter plan at $35/month for 50,000 emails. 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. 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, MailerSend has a median API response time (p50) of 167ms compared to 81ms for Mailtrap.
From July 24th to October 22nd, MailerSend showed an error rate of 0.00% while Mailtrap 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, MailerSend handled <1M messages from July 24th to October 22nd compared to <1M for Mailtrap. MailerSend is currently seeing declining volume, while Mailtrap is seeing declining volume.
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use MailerSend and Mailtrap side by side, route traffic between them, or migrate from one to the other without changing your application code.
MailerSend strengths include designed for both developers and business users with api and visual editor and modern, intuitive ui that is easier to navigate than older platforms. 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. On the other hand, MailerSend drawbacks include available integrations with other tools are basic and limited, while Mailtrap drawbacks include native integration ecosystem is smaller than established competitors.
Use either provider with Knock
Knock enables you to integrate MailerSend, Mailtrap, or any combination of email providers into a single notification workflow. Manage templates, orchestrate cross-channel delivery, and switch providers without changing your code.