# MailerSend AI integration on Definable

> MailerSend is a transactional email service designed for developers to integrate email sending capabilities into their applications.

## What this connects

MailerSend is a transactional email service designed for developers to integrate email sending capabilities into their applications.

Vendor: https://www.mailersend.com/

## Tools available

**23** tools available. First 12:

- `MAILERSEND_CREATE_DOMAIN` — Create Sending Domain — Tool to add a new sending domain to MailerSend. Use when you need to register and configure a domain before sending emails.
- `MAILERSEND_CREATE_SMTP_USER` — Create SMTP User — Tool to create a new SMTP user. Use after domain setup to obtain SMTP credentials.
- `MAILERSEND_CREATE_TOKEN` — Create API Token — Creates a new API token with specified scopes (permissions) for a domain. The token allows programmatic access to MailerSend API endpoints based on granted scopes. WARNING: The token value is only displayed once upon creation and cannot be retrieved later.
- `MAILERSEND_CREATE_WEBHOOK` — Create Webhook — Tool to create a new webhook for a MailerSend domain. Use after you have a domain ID and need to receive event notifications like sent, delivered, opened, etc.
- `MAILERSEND_DELETE_WEBHOOK` — Delete Webhook — Tool to delete an existing webhook. Use when the webhook is no longer needed. Returns empty response on successful deletion (HTTP 204).
- `MAILERSEND_GET_API_QUOTA` — Get API Quota — Tool to retrieve current API usage quota. Use when monitoring API rate limits to avoid exceeding allowed calls.
- `MAILERSEND_GET_DOMAIN` — Get Domain — Tool to retrieve detailed information about a specific sending domain in MailerSend. Returns domain verification status (DKIM, SPF, MX, tracking), settings (click/open tracking, paused status), and metadata (creation/update timestamps). Use this when you need to check if a domain is properly verified and configured for sending emails, or to review domain-specific tracking settings. Note: For detailed DNS record values, use the Get Domain DNS Records action.
- `MAILERSEND_GET_DOMAIN_RECIPIENTS` — List Domain Recipients — Tool to list recipients for a domain. Use after obtaining the domain ID to view recipients with optional pagination.
- `MAILERSEND_GET_DOMAINS` — Get sending domains — Retrieve a paginated list of all sending domains configured in your MailerSend account. Use this to: - View all domains available for sending emails - Check domain verification and DNS status - Filter by verification status to find verified or unverified domains - Review domain settings like tracking and sending preferences Returns domain details including verification status, DNS configuration, and tracking settings.
- `MAILERSEND_GET_GENERAL_RESOURCES` — Get general API resources — Tool to retrieve general API resources and information. Use when you need an overview of all MailerSend endpoints before constructing specific calls.
- `MAILERSEND_GET_IDENTITIES` — List Sender Identities — Retrieves a paginated list of sender identities configured in your MailerSend account. Sender identities are the email addresses or domains authorized to send emails through MailerSend. Each identity includes verification status, reply-to configuration, domain association, and optional personal notes. Use this tool to discover available sender identities before sending emails or to verify which identities are ready for use. Returns: Paginated list of identity objects with metadata including verification status, domain details, and navigation links for pagination.
- `MAILERSEND_GET_MESSAGES` — Get sent messages — Tool to retrieve a paginated list of sent messages. Use after sending emails to view message logs.

## Auth

Auth schemes: `API_KEY`.

## How agents use MailerSend

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

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

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

## Categories

- transactional email — https://definable.ai/apps/category/transactional-email/
- email — https://definable.ai/apps/category/email/

## Related

- HTML page: https://definable.ai/apps/mailersend/
- Same category (transactional email): https://definable.ai/apps/category/transactional-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