Observed arrival · 2026-10-24
Letterport gives agents real inboxes
Letterport gives AI agents email addresses through an API, with incoming mail exposed as JSON and replies kept in-thread.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Developers building email-capable AI agents
- Worth noticing
- Threads are joined by email headers, not subject lines; the page also shows per-recipient delivery states.
Field notes
The page demonstrates inbox creation with POST /v1/inboxes and incoming mail as JSON, including extracted text, thread IDs, spam status, and attachment names. Developers can connect through REST, signed webhooks, or a hosted MCP server, with a Claude Code command shown. It also lists per-recipient quotas, bounce and complaint suppression, and automatic pauses when sending rates rise; custom-domain addresses are marked as early access.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
$PaidCommerce or pricing visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue