Mandrill vs Sparkpost
Compare Mandrill 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–10M | 9th of 10 → | 0 | 0 |
| <1M | 10th of 10 ↑ | 1 | 5 |
From April 13th to July 12th, Knock routed 1M–10M messages through Mandrill and <1M through Sparkpost. Mandrill reported 0 status page updates over the last 90 days, while Sparkpost reported 5.
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 April 13th to July 12th. The top-line number is an average of these daily values: Mandrill averaged 205ms compared to 281ms for Sparkpost. Mandrill's highest daily p50 was 317ms; Sparkpost's was 312ms. Mandrill is 76ms 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, Mandrill has a p90 of 367ms compared to 471ms for Sparkpost. The highest daily p90 was 507ms for Mandrill and 574ms for Sparkpost. Mandrill handles these slower requests 104ms 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, Mandrill reached 844ms at p99 while Sparkpost reached 622ms. The highest daily p99 was 1265ms for Mandrill and 768ms 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.
| Provider | Avg. daily error rate | Highest daily rate | Peak error date | Zero-error days | Days above 0.01% |
|---|---|---|---|---|---|
| 0.01% | 0.43% | Apr 27 | 86 | 5 |
| 0.00% | 0.42% | May 4 | 90 | 1 |
Averaged across the date range, Mandrill shows a 0.01% daily error rate compared to 0.00% for Sparkpost. The highest single-day error rate was 0.43% for Mandrill and 0.42% 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 Mandrill incidents
Recent status page incidents for Mandrill
No incidents reported in the last 90 days
Recent Sparkpost incidents
Recent status page incidents for Sparkpost
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.
Started May 12, 2026 — Resolved May 12, 2026
May 12, 09:38 EDT Resolved - This incident has been resolved. May 12, 09:10 EDT Monitoring - A fix has been implemented and we are monitoring the results. May 12, 08:48 EDT Identified - We’re currently investigating an issue that prevented some customers from updating their payment details. The root cause has been identified, and a fix is being implemented.
Started May 11, 2026 — Resolved May 11, 2026
May 11, 16:02 EDT Resolved - This incident has been resolved. May 11, 15:46 EDT Monitoring - A fix has been implemented and we are monitoring the results. May 11, 14:55 EDT Identified - We are experiencing an elevated level of errors and latency on the Suppression List API for some SparkPost customers. Please retry any 5xx error. Note: This issue does not impact SparkPost customers hosted in the EU.
Started May 9, 2026 — Resolved May 9, 2026
May 9, 18:17 EDT Resolved - This incident has been resolved. May 9, 18:05 EDT Monitoring - A fix has been implemented and we are monitoring the results. May 9, 17:50 EDT Identified - The issue has been identified and a fix is being implemented. May 9, 17:39 EDT Investigating - We are looking into why some messages are seeing delayed delivery.
Started May 8, 2026 — Resolved May 8, 2026
May 8, 07:31 EDT Resolved - This incident has been resolved. May 7, 06:49 EDT Monitoring - A fix has been implemented and we are monitoring the results. May 7, 05:31 EDT Investigating - We are currently investigating this issue.
Pros and cons
Mandrill
Sparkpost
Pros
- Friendly, well-laid-out developer documentation that makes integration straightforward
- Global infrastructure for fast delivery with dedicated IPs and IP address pools
- Solid analytics with reports on deliverability, opens, clicks, bounces, and rejections
- Reuse Mailchimp templates for transactional email with deep ecosystem integration
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 an existing Mailchimp Standard or Premium subscription
- Not available as a standalone service
- Higher cost than some dedicated transactional services
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 Mandrill and Sparkpost?
Mandrill is a transactional email add-on for Mailchimp, suited for teams already using the Mailchimp platform. SparkPost is a data-driven email delivery platform with advanced analytics and predictive tools for high-volume senders. Mandrill is best suited for mailchimp users needing transactional, while Sparkpost is geared toward data-driven, high-volume.
Which is cheaper, Mandrill or Sparkpost?
Included as an add-on to Mailchimp Standard or Premium plans. Pricing is based on email blocks of 25,000 emails, starting at $20/block. Volume discounts apply: $18/block above 500K, scaling down to $10/block above 4M. 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, Mandrill or Sparkpost?
Based on real-world data from Knock, Mandrill has a median API response time (p50) of 205ms compared to 281ms for Sparkpost.
Which is more reliable, Mandrill or Sparkpost?
From April 13th to July 12th, Mandrill showed an error rate of 0.01% 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, Mandrill or Sparkpost?
On the Knock platform, Mandrill handled 1M–10M messages from April 13th to July 12th compared to <1M for Sparkpost. Mandrill volume has remained stable, while Sparkpost is trending upward.
Can I use both Mandrill and Sparkpost together?
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use Mandrill 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 Mandrill vs Sparkpost?
Mandrill strengths include friendly, well-laid-out developer documentation that makes integration straightforward and global infrastructure for fast delivery with dedicated ips and ip address pools. 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, Mandrill drawbacks include requires an existing mailchimp standard or premium subscription, 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 Mandrill, 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.