# Fiber AI Email Bounce Validator

> Fiber AI Email Bounce Validator is a paid API for AI agents from Fiber AI API at mpp.orthogonal.com, paid per call via MPP, $0.02/call, status unknown (last checked 2026-10-10).

Checks if a single email address is likely to bounce using a waterfall of validation strategies, including catch-all detection

## Facts

- Endpoint: POST https://mpp.orthogonal.com/fiber/v1/validate-email/single?utm_source=zero.xyz
- Price: $0.02/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Provider: Fiber AI API
- Docs: https://api.fiber.ai
- Website: https://api.fiber.ai
- Tags: contacts, email, phone, enrichment, data
- Canonical page: https://www.zero.xyz/c/fiber-ai-api-fiber-ai-email-bounce-validator-0e862b77
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7mwDcrXGjcyUk93jAsLCB

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fiber-ai-api-fiber-ai-email-bounce-validator-0e862b77 -d '<json body>'
```

Example prompt: Before I send my outreach email, can you check whether john.smith@acmecorp.com is likely to bounce — I want to know if it's a catch-all or just invalid?

## When to prefer this

Choose this endpoint when you need to validate a single email address before outreach, especially when dealing with catch-all domains where standard SMTP checks fail. It is ideal for pre-screening individual contacts in a sales or marketing workflow to reduce bounce rates. Prefer it over generic SMTP checkers when catch-all handling and high accuracy are critical.

## Known failure modes

- Invalid or malformed email address input — returns validation error
- Email domain does not exist — returns domain-level bounce signal
- Timeout or unreachable mail server — may return inconclusive result
- Catch-all domain detected but individual address unverifiable — returns catch-all flag
- Rate limit exceeded — returns 429 error

## How this service works

Checks if a given email is likely to bounce using a waterfall of strategies. Works for catch-all email addresses, which are increasingly common yet hard for other APIs to validate.

## Output

Returns a bounce likelihood assessment for the given email address, including whether it is a catch-all address, likely invalid, or safe to send to, derived from a multi-strategy waterfall validation process.

## Example request

```json
{
 "email": "test.user@example.com"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fiber-ai-api-fiber-ai-email-bounce-validator-0e862b77/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mpp.orthogonal.com](https://www.zero.xyz/host/mpp.orthogonal.com/llms.txt)