# Mailboxlayer AI integration on Definable

> A simple REST-based JSON API for email address validation and verification.

## What this connects

A simple REST-based JSON API for email address validation and verification.

Vendor: https://mailboxlayer.com/

## Tools available

**1** tools available. First 1:

- `MAILBOXLAYER_CHECK_EMAIL` — Check Email Validity — Tool to validate a single email address. Use when you need to check syntax, domain, SMTP, and meta-flags.

## Auth

Auth schemes: `API_KEY`.

## How agents use Mailboxlayer

Inside a Definable workflow, Mailboxlayer is one of the tools the **Distributor specialist** can call. Example coordination patterns:

- **Researcher → Mailboxlayer** — the Researcher (GPT-5.5) pulls context from Mailboxlayer (records, threads, documents), synthesises findings, and briefs the rest of the team.
- **Writer → Distributor → Mailboxlayer** — the Writer (Claude Opus 4.7) drafts copy in brand voice, the Verifier passes it, then the Distributor writes the result into Mailboxlayer (create record, post message, draft email).
- **Designer / Engineer → Distributor → Mailboxlayer** — the Designer ships an asset or the Engineer ships a code change, the Distributor delivers it via Mailboxlayer (attach file, open PR comment, post status).

The Verifier checks every Mailboxlayer call. On rate limit, schema drift, or auth refresh it self-heals and retries — the workflow completes without manual intervention.

## Categories

- email — https://definable.ai/apps/category/email/
- developer tools — https://definable.ai/apps/category/developer-tools/

## Related

- HTML page: https://definable.ai/apps/mailboxlayer/
- Same category (email): https://definable.ai/apps/category/email/
- All integrations: https://definable.ai/apps/
- Workflow (multi-agent loop): https://definable.ai/workflow/
- Apps llms.txt index: https://definable.ai/llms-apps.txt