postbox.send()194 accounts blocked · 4 of 5 agents · first seen Sep 10
Deprecated SDK call
The quickstart still calls postbox.send(to, html), which postbox-node 4 removed. Agents copy it, the build fails, and they stop before they ever call the API.
- Share of failed tasks
- 24%
- Accounts blocked
- 194
- MRR a month at risk
- $1,940
- Lab trials failed
- 10 of 200
What agents doThe path most agents take, from production and the lab
- The agent reads the quickstartGET /docs/quickstart.md
- It copies the send callawait postbox.send(to, html)
- The build failsTS2339: Property 'send' does not exist
- It guesses other method namespostbox.messages.send, postbox.mail.send
- It stops before the APIProduction sees a key and no send
Where it comes from
/docs/quickstart.md:31
31await postbox.send(to, html);/docs/sdks/node.md
Doesn't mention that send() was removed in 4.0.
In productionAccounts blocked, by the day they made their key
By agent
- claude-code80 · 13%
- codex62 · 16%
- cursor32 · 12%
- gemini-cli20 · 12%
Count, and the share of that agent's API keys it blocked.
Accounts it blocked
Fix
Suggested change
Update the quickstart to postbox.emails.send() and note the 4.0 change in the Node SDK page.
What it costs
$1,940/mo
194 blocked accounts × $10 of MRR per working account. New agent-started accounts that reach a working call bring $6,100 of MRR across 610 accounts.
In the labRun 412, failed trials by task
- install3
- auth1
- webhook5
- billing1