otterpost

A fresh inbox, one click, zero ads.

A throwaway address for signups, free trials, and one-off verification codes — use it instead of your real inbox. Emails land here live, then self-destruct in an hour. No ads, no tracking, no account.

Your address — ready to use

No ads · No trackers · No account. Emails are deleted forever when the timer ends.

1

Grab the address

It's already live — copy it straight into any signup form.

2

Watch emails arrive

Emails appear in real time, safely sandboxed, remote images blocked.

3

Walk away

Everything burns after 60 minutes. Grab a new address any time.

for QA · CI · AI agents

The same inbox, as an API. Wait for the email, extract the OTP — one call each.

Disposable inboxes on a real SMTP server, a deterministic wait call instead of sleeps, and OTP plus link extraction as an endpoint.

const tbx = new Otterpost({ apiKey: process.env.OTTERPOST_API_KEY });
const inbox = await tbx.createInbox({ prefix: "e2e" });
// ...point your signup form at inbox.email...
const msg = await inbox.waitForMessage({ subjectContains: "verification" });
const { otp } = await tbx.extract(msg.id);
Get an API keyRead the docs
POST /v1/inboxes

A fresh address in ~40 ms. Readable local parts, your own prefix, TTL up to 24 hours.

GET /v1/inboxes/:id/wait

Long-poll until the email lands. Filter by subject, sender, or time — the request resolves the moment the message arrives.

GET /v1/messages/:id/extract

OTP and links, parsed for you. Verification and reset links detected; no regex in your test suite.

MCP six tools over stdio

Agents drive the full loop. Claude creates the inbox, signs up somewhere, reads the code — hands-free.

~0.4s
receive → API
1 call
OTP + links out
MCP
built for agents
$0
100 emails a month free

For AI agents

The MCP server exposes the whole flow — create inbox, wait for email, extract OTP — as tools, so agents like Claude Code can verify signup flows end to end on their own.

{
  "mcpServers": {
    "otterpost": {
      "type": "stdio",
      "command": "node",
      "args": ["./packages/mcp/dist/index.js"],
      "env": { "OTTERPOST_API_KEY": "otter_..." }
    }
  }
}

Pricing

One flat price. No meters, no overage math.

Free

$0
  • 2 concurrent inboxes
  • 100 emails a month
  • 1 hour inbox lifetime
Start free

Pro

For teams and CI
$15/mo
  • 50 concurrent inboxes
  • 5,000 emails a month
  • 24 hour inbox lifetime
  • priority support
Get Pro

Get an API key

Otterpost is self-hostable and keys are minted with the admin CLI. For a key on the hosted instance, write to us and we set you up the same day.

pnpm --filter @otterpost/server cli keys:create --plan free
# API key created. The secret below is shown ONCE — store it now.
#   otter_...
Request a hosted key

Questions

What happens to emails?

Messages live only for the inbox lifetime (up to an hour on free, a day on pro) and are deleted when the inbox expires or when you delete it. Nothing is archived.

Can senders see anything?

No. The SMTP server accepts email for active inboxes only and rejects everything else during the SMTP conversation, so senders learn nothing about usage or quotas.

Do you send email?

No. Otterpost is receive-only — there is no sending code path in the product at all.

What are the limits?

Free: 2 concurrent inboxes, 100 emails a month, 1 hour lifetime. Pro: 50 inboxes, 5,000 emails, 24 hours. The API allows 60 requests a minute per key; the wait endpoint is exempt.