Send email, buy dedicated inboxes, manage custom subdomains, and retrieve inbound messages through per-request email APIs. Supports shared relay sending, subdomain sender identities, forwarding inboxes, message storage, and attachment access.
Use for sending outbound emails, creating receiving inboxes, reading inbound messages, managing custom email subdomains, agent email workflows, forwarding inboxes, reply handling, verification messages, customer outreach, and per-message email delivery.
| Method | Path |
|---|---|
| POST | api/inbox/buy Buy an inbox on stableemail.dev ($1, 30 days). forwardTo is optional — omit it to use as a programmatic mailbox via the messages API (retainMessages enabled automatically). Message content and attachments are retained for 90 days. |
| POST | api/inbox/cancel Cancel inbox and get pro-rata refund (free) |
| POST | api/inbox/messages List messages in your inbox ($0.001) |
| POST | api/inbox/messages/delete Delete a single inbox message (free) |
| POST | api/inbox/messages/read Read a single inbox message ($0.001). Returns text, HTML, and attachment download URLs (1hr expiry). Message content available for 90 days from receipt. |
| POST | api/inbox/send Send email from your forwarding inbox on stableemail.dev ($0.005) |
| GET | api/inbox/status Check inbox status (free) |
| POST | api/inbox/topup Top up a forwarding inbox for 30 days ($1) |
| POST | api/inbox/topup/quarter Top up a forwarding inbox for 90 days ($2.50, save 17%) |
| POST | api/inbox/topup/year Top up a forwarding inbox for 365 days ($8, save 34%) |
| POST | api/inbox/update Update inbox settings (free) |
| POST | api/send Send an email from "StableEmail" <relay@stableemail.dev> ($0.02) |
| POST | api/subdomain/buy Purchase a custom email subdomain on stableemail.dev ($5) |
| POST | api/subdomain/inbox/create Create an inbox on your subdomain ($0.25). Max 100 inboxes, 500 messages each. Message content and attachments retained for 90 days. |
| POST | api/subdomain/inbox/delete Delete an inbox on a subdomain (free) |
| POST | api/subdomain/inbox/list List inboxes on a subdomain (free) |
| POST | api/subdomain/inbox/messages List messages in a subdomain inbox ($0.001) |
| POST | api/subdomain/inbox/messages/delete Delete a single subdomain inbox message (free) |
| POST | api/subdomain/inbox/messages/read Read a single subdomain inbox message ($0.001). Returns text, HTML, and attachment download URLs (1hr expiry). Message content available for 90 days from receipt. |
| POST | api/subdomain/inbox/update Update subdomain inbox settings (free) |
| POST | api/subdomain/send Send email from your custom subdomain on stableemail.dev ($0.005) |
| POST | api/subdomain/signers Manage authorized signers for a subdomain (free) |
| GET | api/subdomain/status Check subdomain status (free) |
| POST | api/subdomain/update Update subdomain settings (free) |