Mailjet vs Sparkpost
Compare Mailjet 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) |
|---|---|---|---|---|
| <1M | 6th of 10 ↑ | 1 | 1 |
| <1M | 10th of 10 ↓ | 2 | 4 |
From June 13th to September 10th, Knock routed <1M messages through Mailjet and <1M through Sparkpost. Mailjet reported 1 status page update over the last 90 days, while Sparkpost reported 4.
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 13th to September 10th. The top-line number is an average of these daily values: Mailjet averaged 403ms compared to 409ms for Sparkpost. Mailjet's highest daily p50 was 489ms; Sparkpost's was 554ms. 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, Mailjet has a p90 of 582ms compared to 567ms for Sparkpost. The highest daily p90 was 841ms for Mailjet and 749ms for Sparkpost. Both providers show similar performance at this percentile, indicating comparable consistency.
The 99th percentile (p99) represents the long tail — the slowest 1% of requests. Averaged across all days, Mailjet reached 664ms at p99 while Sparkpost reached 737ms. The highest daily p99 was 2503ms for Mailjet and 1427ms for Sparkpost, indicating the worst-case response time during spikes or provider-side congestion. Mailjet 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% | Jun 13 | 90 | 0 |
| 0.00% | 0.00% | Jun 12 | 91 | 0 |
Averaged across the date range, Mailjet shows a 0.00% daily error rate compared to 0.00% for Sparkpost. The highest single-day error rate was 0.00% for Mailjet 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 Mailjet incidents
Recent status page incidents for Mailjet
Started Sep 4, 2026 — Resolved Sep 4, 2026
Sep 4, 12:55 UTC Resolved - This incident has been resolved. Sep 4, 12:23 UTC 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. Sending to other email providers is not affected.
Recent Sparkpost incidents
Recent status page incidents for Sparkpost
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.)
Started Jul 24, 2026 — Resolved Jul 24, 2026
Jul 24, 14:44 EDT Resolved - This incident has been resolved. Jul 24, 13:29 EDT Update - We have implemented additional tuning to handle the significant influx of mail due to the AWS network outage and we are seeing improvement in delivery rates We are seeing significant recovery and expect most mail to be fully delivered in the next 30-35 minutes. Estimated time for full recovery is 80-90 minutes. We are continuing to look for additional optimizations and monitor the issue. Jul 24, 09
Started Jun 29, 2026 — Resolved Jun 29, 2026
Jun 29, 12:46 EDT Resolved - This incident has been resolved. Jun 29, 12:05 EDT Monitoring - There was a combination of events that caused a short period of slowdown. That slowdown has already recovered and we are monitoring to ensure we do not see it again. Jun 29, 11:58 EDT Investigating - We are investigating the delay and the impact. We will post once we know more.
Pros and cons
Mailjet
Sparkpost
Pros
- Hybrid support for both marketers and developers in a single platform
- Unique real-time collaboration features for team-based template editing
- EU-only data processing for companies with strict data residency requirements
- Powers email delivery for over 130,000 companies including Microsoft and DHL
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
- Activated automation workflows cannot be edited, requiring new workflows for any changes
- Some analytics and deliverability tools are locked behind higher pricing plans
- Deliverability can lag behind specialists like Postmark
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 Mailjet and Sparkpost?
Mailjet is a collaborative email platform with real-time editing and combined transactional and marketing capabilities. SparkPost is a data-driven email delivery platform with advanced analytics and predictive tools for high-volume senders. Mailjet is best suited for team collaboration + marketing, while Sparkpost is geared toward data-driven, high-volume.
Which is cheaper, Mailjet or Sparkpost?
Free tier includes 200 emails per day (6,000/month). Paid plans start at $17/month for 15,000 emails with no daily limit. Premium plans start at $105/month for 100,000 emails. 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, Mailjet or Sparkpost?
Based on real-world data from Knock, Mailjet has a median API response time (p50) of 403ms compared to 409ms for Sparkpost.
Which is more reliable, Mailjet or Sparkpost?
From June 13th to September 10th, Mailjet 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, Mailjet or Sparkpost?
On the Knock platform, Mailjet handled <1M messages from June 13th to September 10th compared to <1M for Sparkpost. Mailjet is currently trending upward in adoption, while Sparkpost is seeing declining volume.
Can I use both Mailjet and Sparkpost together?
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use Mailjet 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 Mailjet vs Sparkpost?
Mailjet strengths include hybrid support for both marketers and developers in a single platform and unique real-time collaboration features for team-based template editing. 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, Mailjet drawbacks include activated automation workflows cannot be edited, requiring new workflows for any changes, 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 Mailjet, 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.