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Email API benchmarks

A real-time dashboard of email provider performance

Customer Communication
Email Marketing
Developer Tools

Today we're releasing email API benchmarks, a real-time dashboard of email provider performance to help you compare and choose. The dashboard is powered by the billions of API requests Knock sends to downstream providers like SendGrid, Resend, Postmark, and more. We've aggregated this data to highlight important metrics (like response time and error rate) to help you compare email providers, not based on hype, but on their real-world performance data.

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We're excited to get this product out into the community. Hopefully this data adds another dimension to how you're evaluating your email tools. Let us know what other metrics you'd like to see included here in the next version!

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At Knock, we get asked "which email provider should I use?" all the time. Until now, comparing email provider performance has always been harder than it should be. So we turned to our own data. Every year, Knock sends billions of API requests to downstream email providers. With email API benchmarks, we've aggregated this data to highlight important metrics across different email providers to help you decide which service to use for your product. Check it out, and tell us what you think. What other metrics do you want to see?

Will you add a chatbox so I can ask an AI how to read these benchmarks? Sometimes there is a key parameter that is not obvious that matters more than many others. Congrats on the launch!

I also wanted to share some of the insights we pulled from this data set. It updates everyday, so will be different tomorrow, but here are some high level stats about the performance of these APIs:

API response time
Most email APIs had a median response time of less than 500 ms.

But the three fastest providers on average were: SendGrid at 22 ms

Postmark at 33 ms

Resend at 79 ms

At p99, the long tail of requests, SendGrid still wins with an average of 157 ms.

⚠️ Error rate

Most email APIs have an average daily error rate close to 0.00%.

But peak daily error rates were grouped between 0.02% and 3.41%.

AWS SES had the most days with error rates below 0.01%, covering the entire 90 day window.

👏🏼 Adoption

We looked at both sending volume on Knock and channel growth.

Users sent over 500M+ messages with SendGrid over the last 90 days.

But Resend had the most new channels created, continuing it’s upward trend.

At this point we have a lot of data about how each email provider operates at a very high scale. We're thrilled to make this available to all so folks can make informed choices about the provider they should pick. All powered by our Clickhouse cluster.

Excited to share our email API benchmarks with the Producthunt community! Great work @scottjstrand, @jeff_everhart1 , and @connor_lindsey !

great stuff. I know an agency, charging 4-5k/m for building and maintaining these kind of dashboards. They won't be happy to hear about your product :)

Congrats on the launch! The API benchmarks are a massive gift to the dev community.


I’m interested in the AI Agent workflow on the homepage. It’s a bold vision. However, I’m curious about the transition from the Agent qualification to the Hard-Coded branching logic.


It feels like there's a huge opportunity to make that messaging logic as dynamic as the Agent itself. I’ve mapped out a specific way to bridge that logic gap for Enterprise-tier users. Mind if I share that insight with you?