MailerSend vs Mailgun
Compare MailerSend and Mailgun 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 | 8th of 10 ↑ | 0 | 1 |
| 100M–500M | 5th of 10 → | 5 | 9 |
From March 24th to June 22nd, Knock routed <1M messages through MailerSend and 100M–500M through Mailgun. MailerSend reported 1 status page update over the last 90 days, while Mailgun reported 9.
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 |
|---|---|---|---|---|
| 242ms | 505ms | 577ms | 877ms |
| 133ms | 187ms | 233ms | 483ms |
The chart above shows each provider's daily median response time (p50) from March 24th to June 22nd. The top-line number is an average of these daily values: MailerSend averaged 242ms compared to 133ms for Mailgun. MailerSend's highest daily p50 was 586ms; Mailgun's was 149ms. Mailgun is 109ms 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 505ms compared to 187ms for Mailgun. The highest daily p90 was 1993ms for MailerSend and 829ms for Mailgun. Mailgun handles these slower requests 318ms 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 877ms at p99 while Mailgun reached 483ms. The highest daily p99 was 8277ms for MailerSend and 3152ms for Mailgun, indicating the worst-case response time during spikes or provider-side congestion. Mailgun 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% | 0.08% | Jun 2 | 89 | 2 |
| 0.00% | 0.00% | Mar 24 | 91 | 0 |
Averaged across the date range, MailerSend shows a 0.00% daily error rate compared to 0.00% for Mailgun. The highest single-day error rate was 0.08% for MailerSend and 0.00% for Mailgun. 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 Apr 12, 2026 — Resolved Apr 12, 2026
Status: Complete Maintenance has completed Affected components MailerSend APP (Under maintenance)
Recent Mailgun incidents
Recent status page incidents for Mailgun
Started Jun 18, 2026 — Resolved Jun 18, 2026
Jun 18, 03:24 PDT Resolved - This incident has been resolved. Jun 18, 03:11 PDT Monitoring - A fix has been implemented and we are monitoring the results. Jun 18, 02:53 PDT Identified - The issue has been identified and a fix is being implemented. Jun 18, 02:11 PDT Update - We are continuing to investigate this issue. Jun 18, 01:34 PDT Investigating - Customers using the events/logs APIs or viewing logs in the customer portal may see delays in some events appearing. These delays are
Started Jun 16, 2026 — Resolved Jun 16, 2026
Jun 16, 10:34 PDT Resolved - This incident has been resolved. Jun 16, 09:16 PDT Monitoring - A fix has been implemented and we are monitoring the results. Jun 16, 08:48 PDT Update - We are continuing to investigate this issue. Jun 16, 08:08 PDT Update - We are continuing to investigate this issue. Jun 16, 07:28 PDT Investigating - Logs are currently experiencing delays of 15 minutes in Mailgun's US region. Outbound processing, inbound processing, and webhook delivery are operating n
Started Jun 5, 2026 — Resolved Jun 5, 2026
Jun 5, 07:15 PDT Resolved - This incident has been resolved. Jun 5, 07:04 PDT Monitoring - A fix has been implemented and we are monitoring results. Outbound processing, inbound processing, and webhook delivery continue operating normally. Jun 5, 06:26 PDT Investigating - Logs are currently experiencing delays of 15 minutes in Mailgun's US region. Outbound processing, inbound processing, and webhook delivery are operating normally.
Started Jun 4, 2026 — Resolved Jun 4, 2026
Jun 4, 14:04 PDT Resolved - This incident has been resolved. Jun 4, 13:48 PDT Monitoring - Logs are flowing normally and engineers continue to monitor. Jun 4, 12:52 PDT Update - We are continuing to investigate this issue. Outbound processing, inbound processing, and webhook delivery continue to operate normally. Jun 4, 11:42 PDT Update - We are continuing to investigate this issue. Jun 4, 11:01 PDT Investigating - Logs are currently experiencing delays of 15 minutes in Mailgun
Started May 25, 2026 — Resolved May 25, 2026
May 25, 08:55 PDT Resolved - This incident has been resolved. May 25, 08:45 PDT Monitoring - A fix has been implemented and we are monitoring the results. May 25, 08:35 PDT Update - We are continuing to work on a fix for this issue. May 25, 07:46 PDT Identified - The issue has been identified and a fix is being implemented. May 25, 07:10 PDT Update - We are continuing to investigate this issue. May 25, 06:38 PDT Investigating - We are currently investigating this issue. May 25,
Pros and cons
MailerSend
Mailgun
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
- Well-written documentation with comprehensive guides and best practices for deliverability
- Robust deliverability support with optional expert pairing to optimize sending
- Powerful inbound email processing with customizable routing rules
- Trusted by Lyft, American Express, and Wikipedia since 2010
Cons
- Available integrations with other tools are basic and limited
- Fewer advanced features than enterprise platforms
- Smaller ecosystem compared to established competitors
Cons
- Requires familiarity with email protocols and API integrations
- Pricing tiers can be confusing
- Email template features are basic without the Mailjet editor
Frequently asked questions
What is the difference between MailerSend and Mailgun?
Mailersend is an intuitive transactional email and SMS service by Mailgun, designed for growing businesses. Mailgun is a developer-focused email API platform owned by Sinch, known for flexible sending and receiving capabilities. MailerSend is best suited for growing saas + e-commerce, while Mailgun is geared toward developer-focused sending + receiving.
Which is cheaper, MailerSend or Mailgun?
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 100 emails per day with no expiration. Paid plans start at $15/month for 10,000 emails with overages at $1.80/1K. The best value depends on your sending volume. Use the pricing calculator above to compare costs at your expected volume.
Which is faster, MailerSend or Mailgun?
Based on real-world data from Knock, MailerSend has a median API response time (p50) of 242ms compared to 133ms for Mailgun.
Which is more reliable, MailerSend or Mailgun?
From March 24th to June 22nd, MailerSend showed an error rate of 0.00% while Mailgun 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.
Which is more popular, MailerSend or Mailgun?
On the Knock platform, MailerSend handled <1M messages from March 24th to June 22nd compared to 100M–500M for Mailgun. MailerSend is currently trending upward in adoption, while Mailgun volume has remained stable.
Can I use both MailerSend and Mailgun together?
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use MailerSend and Mailgun 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 MailerSend vs Mailgun?
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. Mailgun strengths include well-written documentation with comprehensive guides and best practices for deliverability and robust deliverability support with optional expert pairing to optimize sending. On the other hand, MailerSend drawbacks include available integrations with other tools are basic and limited, while Mailgun drawbacks include requires familiarity with email protocols and api integrations.
Use either provider with Knock
Knock enables you to integrate MailerSend, Mailgun, or any combination of email providers into a single notification workflow. Manage templates, orchestrate cross-channel delivery, and switch providers without changing your code.