DeliverabilityComing soon
DKIM, SPF, DMARC — what they actually do
A grounded look at the three DNS records every sender learns about the hard way, and why send0 verifies, watches, and alerts on all three by default.
8 min readRead
Blog · send0
Notes from the infrastructure layer.
Engineering posts, product updates, and unopinionated takes on deliverability — written by the team actually running the pager.
Featured
CompanyComing soon
Why we're building send0
We rebuilt email, WhatsApp, and SMS onto one SDK because the status quo was five vendors and three dashboards. Here's the short version of the thesis.
5 min readComing soon
Latest posts
5 drafts in the queueEngineeringComing soon
One API surface, three channels
How we designed the send0 SDK so adding WhatsApp or SMS to an existing email integration is a one-line diff, not a rewrite.
7 min readRead
EngineeringComing soon
Idempotency keys done right
Retries are unavoidable. Duplicate emails are not. A walk through how send0 makes POST /v1/emails safe to retry and easy to reason about.
6 min readRead
ProductComing soon
AI channel routing, explained
What the router actually learns, when it deflects a send from email to WhatsApp, and how we measure whether it's working.
9 min readRead
EngineeringComing soon
Why we ship test-mode keys first
sk_test_ keys aren't a checkbox — they shape how your team writes code. Here's what a proper test environment buys you.
4 min readRead
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