Mailgun vs Sparkpost
Compare Mailgun and Sparkpost 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) |
|---|---|---|---|---|
| 100M–500M | 5th of 10 → | 4 | 12 |
| <1M | 10th of 10 ↓ | 3 | 6 |
From July 4th to October 2nd, Knock routed 100M–500M messages through Mailgun and <1M through Sparkpost. Mailgun reported 12 status page updates over the last 90 days, while Sparkpost reported 6.
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 4th to October 2nd. The top-line number is an average of these daily values: Mailgun averaged 120ms compared to 335ms for Sparkpost. Mailgun's highest daily p50 was 133ms; Sparkpost's was 554ms. Mailgun is 215ms 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, Mailgun has a p90 of 170ms compared to 558ms for Sparkpost. The highest daily p90 was 197ms for Mailgun and 648ms for Sparkpost. Mailgun handles these slower requests 388ms 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, Mailgun reached 222ms at p99 while Sparkpost reached 727ms. The highest daily p99 was 506ms for Mailgun and 901ms for Sparkpost, 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% | 0.01% | Aug 27 | 90 | 0 |
| 0.00% | 0.00% | Jul 4 | 91 | 0 |
Averaged across the date range, Mailgun shows a 0.00% daily error rate compared to 0.00% for Sparkpost. The highest single-day error rate was 0.01% for Mailgun and 0.00% for Sparkpost. 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 Mailgun incidents
Recent status page incidents for Mailgun
Started Sep 30, 2026 — Resolved Sep 30, 2026
Sep 30, 02:58 PDT Resolved - This incident has been resolved. Sep 30, 02:48 PDT Monitoring - A fix has been implemented and we are monitoring the results. Sep 30, 02:38 PDT Identified - The issue has been identified and a fix is being implemented. Sep 30, 02:16 PDT Investigating - We are currently investigating this issue.
Started Sep 14, 2026 — Resolved Sep 14, 2026
Sep 14, 03:13 PDT Resolved - This incident has been resolved. Sep 14, 02:55 PDT Monitoring - A fix has been implemented and we are monitoring the results. Sep 14, 02:15 PDT Investigating - We are currently investigating this issue.
Started Sep 4, 2026 — Resolved Sep 4, 2026
Sep 4, 07:33 PDT Resolved - This incident has been resolved. Sep 4, 07:21 PDT Monitoring - A fix has been implemented and we are monitoring the results. Sep 4, 07:16 PDT Investigating - We are currently investigating this issue.
Started Sep 4, 2026 — Resolved Sep 4, 2026
Sep 4, 05:54 PDT Resolved - Microsoft has resolved the underlying issue, we are seeing deliveries to M365 process normally. Sep 4, 05:22 PDT Update - We are continuing to monitor for any further issues. Sep 4, 05:20 PDT Monitoring - Starting around 08:00 UTC, Microsoft began experiencing an incident causing an increased volume of deferred emails across all M365 regions. The affected responses are returning "451 4.7.500 Server busy". Our teams are actively monitoring the situation. Send
Started Aug 31, 2026 — Resolved Aug 31, 2026
Aug 31, 15:01 PDT Resolved - Event queues have caught up and events are processing normally. Aug 31, 14:28 PDT Update - The event processing backlog is steadily decreasing, and we’re continuing to monitor the recovery. We expect all delays to be resolved within the hour. Aug 31, 13:43 PDT Update - The event processing backlog is steadily decreasing, and we’re continuing to monitor the recovery. Aug 31, 13:13 PDT Update - The event processing backlog is steadily decreasing, and we’re co
Recent Sparkpost incidents
Recent status page incidents for Sparkpost
Started Oct 1, 2026 — Resolved Oct 1, 2026
Oct 1, 13:36 EDT Resolved - This issue has been resolved. Since our changes went in, we've seen no further delivery delays, including through peak sending periods. Email is being delivered normally. We apologize for the disruption and thank you for your patience. Oct 1, 13:16 EDT Monitoring - We've made changes to address the intermittent delivery delays. Since then, email has been delivered without delay, including during peak sending periods that previously caused the slowdowns. We're wa
Started Sep 17, 2026 — Resolved Sep 17, 2026
Sep 17, 06:00 EDT Resolved - This incident has been resolved. Sep 17, 05:47 EDT Monitoring - A fix has been implemented and we are monitoring the results. Sep 17, 05:06 EDT Investigating - We are investigating an increase in delivery latency for some outbound messages. (NOTE: This does not impact our customers hosted in the EU.)
Started Sep 14, 2026 — Resolved Sep 14, 2026
Sep 14, 12:46 EDT Resolved - The data has all been posted. We apologize for the delay. Sep 14, 12:31 EDT Monitoring - Data is reprocessed and loads are completing. Full data recovery expected in the next 30 minutes. Sep 14, 10:59 EDT Identified - We know what has caused the data delay and are working to get the data posted. Sep 14, 10:19 EDT Investigating - Health score and Cohort data is delayed.
Started Aug 27, 2026 — Resolved Aug 27, 2026
Aug 27, 18:56 EDT Resolved - The Apple bounce levels have maintained at pre incident levels during our monitoring phase. Our clean up of the bad suppressions has finished. This incident is resolved. Aug 27, 15:28 EDT Monitoring - We have seen recovery of the Apple private relay domain to pre-event bounce levels. Our team is actively working on automatically removing any suppressions that were created by this event. We anticipate the cleanup to be completed by 6PM EDT. Aug 27, 15:10 EDT
Started Aug 19, 2026 — Resolved Aug 19, 2026
Aug 19, 15:58 EDT Resolved - This incident has been resolved. Aug 19, 15:44 EDT Monitoring - A fix has been implemented and we are monitoring the results. Aug 19, 14:52 EDT Investigating - We are investigating an increase in delivery latency for some outbound messages. (NOTE: This does not impact our customers hosted in the US.)
Pros and cons
Mailgun
Sparkpost
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
Pros
- Delivers nearly 40% of all commercial email worldwide
- Subaccount support for isolated sending streams under one billing account
- On-premise mail sending solution available for very high volume workloads
- Great analytics tools with predictive health scores for email deliverability
Cons
- Requires familiarity with email protocols and API integrations
- Pricing tiers can be confusing
- Email template features are basic without the Mailjet editor
Cons
- Documentation can be hard to navigate with less beginner-friendly getting started content
- Higher price point than basic providers
- Now part of Bird (formerly MessageBird), which may affect product direction
Frequently asked questions
What is the difference between Mailgun and Sparkpost?
Mailgun is a developer-focused email API platform owned by Sinch, known for flexible sending and receiving capabilities. SparkPost is a data-driven email delivery platform with advanced analytics and predictive tools for high-volume senders. Mailgun is best suited for developer-focused sending + receiving, while Sparkpost is geared toward data-driven, high-volume.
Which is cheaper, Mailgun or Sparkpost?
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. Free tier includes 500 emails per month with community support. Paid plans start at $20/month for 50,000 emails with premium deliverability features. The best value depends on your sending volume. Use the pricing calculator above to compare costs at your expected volume.
Which is faster, Mailgun or Sparkpost?
Based on real-world data from Knock, Mailgun has a median API response time (p50) of 120ms compared to 335ms for Sparkpost.
Which is more reliable, Mailgun or Sparkpost?
From July 4th to October 2nd, Mailgun showed an error rate of 0.00% while Sparkpost 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, Mailgun or Sparkpost?
On the Knock platform, Mailgun handled 100M–500M messages from July 4th to October 2nd compared to <1M for Sparkpost. Mailgun volume has remained stable, while Sparkpost is seeing declining volume.
Can I use both Mailgun and Sparkpost together?
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use Mailgun and Sparkpost 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 Mailgun vs Sparkpost?
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. Sparkpost strengths include delivers nearly 40% of all commercial email worldwide and subaccount support for isolated sending streams under one billing account. On the other hand, Mailgun drawbacks include requires familiarity with email protocols and api integrations, while Sparkpost drawbacks include documentation can be hard to navigate with less beginner-friendly getting started content.
Use either provider with Knock
Knock enables you to integrate Mailgun, Sparkpost, or any combination of email providers into a single notification workflow. Manage templates, orchestrate cross-channel delivery, and switch providers without changing your code.