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 ↑ | 2 | 3 |
 | 100M–500M | 5th of 10 → | 2 | 3 |
From January 1st to March 31st, Knock routed <1M messages through Mailersend and 100M–500M through Mailgun. Mailersend reported 3 status page updates over the last 90 days, while Mailgun reported 3.
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 |
|---|---|---|---|---|
| 264ms | 548ms | 589ms | 802ms |
| 125ms | 182ms | 226ms | 386ms |
The chart above shows each provider's daily median response time (p50) from January 1st to March 31st. The top-line number is an average of these daily values: Mailersend averaged 264ms compared to 125ms for Mailgun. Mailersend's highest daily p50 was 469ms; Mailgun's was 147ms. Mailgun is 139ms 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 548ms compared to 182ms for Mailgun. The highest daily p90 was 1048ms for Mailersend and 220ms for Mailgun. Mailgun handles these slower requests 366ms 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 802ms at p99 while Mailgun reached 386ms. The highest daily p99 was 12094ms for Mailersend and 451ms 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% |
|---|---|---|---|---|---|
| 0.01% | 0.06% | Feb 18 | 84 | 4 |
| 0.00% | 0.03% | Mar 17 | 89 | 1 |
Averaged across the date range, Mailersend shows a 0.01% daily error rate compared to 0.00% for Mailgun. The highest single-day error rate was 0.06% for Mailersend and 0.03% 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
Ongoing since Mar 30, 2026
Status: Scheduled Our database service provider will be performing scheduled maintenance that should take no longer than 15 minutes. During this time, you may experience brief interruptions when signing up, logging in, or switching accounts on MailerSend. We appreciate your patience and thank you for your continued trust in our services. Affected components MailerSend APP (Under maintenance)
Started Mar 3, 2026 — Resolved Mar 3, 2026
Status: Complete Maintenance has completed Affected components Bulk endpoint (Under maintenance) SMTP (Under maintenance) Delivery time (Under maintenance) Email sending API (Under maintenance) Deliverability rate (Under maintenance)
Started Feb 19, 2026 — Resolved Feb 19, 2026
Status: Resolved The issue has been resolved and systems have returned to normal. We’ll continue monitoring to ensure ongoing stability. Thank you for your patience. Affected components MailerSend APP (Operational)
Recent Mailgun incidents
Recent status page incidents for Mailgun
Started Mar 19, 2026 — Resolved Mar 19, 2026
Mar 19, 11:53 PDT Resolved - A fix has been deployed and systems are back to normal.Mar 19, 11:43 PDT Identified - Some requests may be incorrectly failing with 401 error codes in our US region.
Started Mar 13, 2026 — Resolved Mar 13, 2026
Mar 13, 05:49 PDT Resolved - The incident has been resolved.Mar 13, 05:33 PDT Monitoring - A fix has been implemented and we are monitoring the results.Mar 13, 05:19 PDT Identified - The issue has been identified and a fix is being implemented.Mar 13, 04:56 PDT Update - We are continuing to investigate this issue.Mar 13, 04:29 PDT Investigating - We are currently investigating this issue.
Started Feb 25, 2026 — Resolved Feb 25, 2026
Feb 25, 13:45 PST Resolved - This incident has been resolved.Feb 25, 13:36 PST Monitoring - A fix has been implemented and we are monitoring the results.Feb 25, 12:25 PST Update - We are continuing to work on a fix for this issue.Feb 25, 11:47 PST Update - We are continuing to work on a fix for this issue.Feb 25, 11:30 PST Update - We are continuing to work on a fix for this issue.Feb 25, 11:29 PST Identified - Domain verification is also impacted. Increased chances of domain verification failin
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 264ms compared to 125ms for Mailgun.
Which is more reliable, Mailersend or Mailgun?
From January 1st to March 31st, Mailersend showed an error rate of 0.01% 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 January 1st to March 31st 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.