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Mailjet vs Sparkpost

Compare Mailjet and Sparkpost based on observed API performance, features, and pricing

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Live performance comparison

Real-world performance data from messages sent through Knock

Jan 22, 2026Apr 21, 2026
Updated daily
ProviderMessage volumeGrowthStatus page updates (30d)Status page updates (90d)
Mailjet
Mailjet
<1M
6th of 10 00
Sparkpost
Sparkpost
<1M
10th of 10 00

From January 22nd to April 21st, Knock routed <1M messages through Mailjet and <1M through Sparkpost. Mailjet reported 0 status page updates over the last 90 days, while Sparkpost reported 0.

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.

ProviderMedian (p50)p90p95p99
Mailjet
Mailjet
412ms
538ms598ms775ms
Sparkpost
Sparkpost
285ms
348ms388ms551ms

The chart above shows each provider's daily median response time (p50) from January 22nd to April 21st. The top-line number is an average of these daily values: Mailjet averaged 412ms compared to 285ms for Sparkpost. Mailjet's highest daily p50 was 490ms; Sparkpost's was 336ms. Sparkpost is 127ms 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, Mailjet has a p90 of 538ms compared to 348ms for Sparkpost. The highest daily p90 was 20309ms for Mailjet and 402ms for Sparkpost. Sparkpost handles these slower requests 190ms 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, Mailjet reached 775ms at p99 while Sparkpost reached 551ms. The highest daily p99 was 20345ms for Mailjet and 31566ms for Sparkpost, indicating the worst-case response time during spikes or provider-side congestion. Sparkpost 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.

ProviderAvg. daily error rateHighest daily ratePeak error dateZero-error daysDays above 0.01%
Mailjet
Mailjet
0.14%
12.99%Apr 13873
Sparkpost
Sparkpost
0.19%
3.41%Feb 24901

Averaged across the date range, Mailjet shows a 0.14% daily error rate compared to 0.19% for Sparkpost. The highest single-day error rate was 12.99% for Mailjet and 3.41% 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

No incidents reported in the last 90 days

Recent Sparkpost incidents

Recent status page incidents for Sparkpost

No incidents reported in the last 90 days

Pros and cons

Mailjet
Mailjet

Sparkpost
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 412ms compared to 285ms for Sparkpost.

Which is more reliable, Mailjet or Sparkpost?

From January 22nd to April 21st, Mailjet showed an error rate of 0.14% while Sparkpost showed 0.19%. 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 January 22nd to April 21st compared to <1M for Sparkpost. Mailjet volume has remained stable, while Sparkpost volume has remained stable.

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.