MailerSend is a transactional email service designed for developers to integrate email sending capabilities into their applications.
MailerSend is a transactional email service designed for developers to integrate email sending capabilities into their applications. On Nagent, MailerSend is exposed as a fully-configurable transactional email integration that any agent can call — 23 actions, and API key authentication. No code is required to wire MailerSend into your workflow — connect it once via the External Integrations panel and reuse it across every agent you build.
Agent builders use MailerSend to automate the kinds of tasks transactional email teams previously handled manually. Concrete examples — each one is a single agent step in Nagent — include:
Every action and trigger is paired with a structured input/output schema (visible in the sections below), so when you wire MailerSend into Helix — our agentic agent builder — the editor knows exactly what each step expects and produces. Configure once, deploy anywhere across your Nagent agents.
Every operation an agent can call against MailerSend, with input parameters and output schema. Drop these into any step of an agent built in Helix.
MAILERSEND_CREATE_DOMAINTool to add a new sending domain to MailerSend. Use when you need to register and configure a domain before sending emails.
Input parameters
Fully qualified domain name to add for sending emails. Must be unique, lowercase, available, and resolvable.
Alphanumeric subdomain to use for return path (e.g., 'rp'). If not provided, a default will be used.
Alphanumeric subdomain for custom tracking (e.g., 'track'). Enables custom click and open tracking.
Alphanumeric subdomain for inbound routing (e.g., 'inbound'). Used for receiving emails.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_CREATE_SMTP_USERTool to create a new SMTP user. Use after domain setup to obtain SMTP credentials.
Input parameters
Display name for the SMTP user (max 50 characters).
Whether the SMTP user should be enabled. Defaults to True.
ID of the domain to associate with this SMTP user.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_CREATE_TOKENCreates 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.
Input parameters
A descriptive name for the new API token (max 50 characters).
List of permission scopes to grant this token. Available scopes include: email_full, domains_read, domains_full, activity_read, activity_full, analytics_read, analytics_full, tokens_full, webhooks_full, templates_full, suppressions_read, suppressions_full, sms_full, sms_read, email_verification_read, email_verification_full, inbounds_full, recipients_read, recipients_full, sender_identity_read, sender_identity_full, users_read, users_full, smtp_users_read, smtp_users_full.
The ID of the domain to associate with this token. Use GET_DOMAINS action to retrieve available domain IDs.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_CREATE_WEBHOOKTool 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.
Input parameters
The callback URL where MailerSend will send POST requests (max 191 characters).
The name of the webhook (max 191 characters).
List of events the webhook listens for. Valid events include: activity.sent, activity.delivered, activity.soft_bounced, activity.hard_bounced, activity.deferred, activity.opened, activity.opened_unique, activity.clicked, activity.clicked_unique, activity.unsubscribed, activity.spam_complaint, activity.survey_opened, activity.survey_submitted, sender_identity.verified, maintenance.start, maintenance.end, inbound_forward.failed, email_single.verified, email_list.verified, bulk_email.completed.
Whether the webhook is enabled immediately after creation. Defaults to true.
Webhook version (1 or 2). Version 1 is recommended, version 2 is legacy. If not specified, uses API default.
The ID of the domain to attach the webhook to.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_DELETE_WEBHOOKTool to delete an existing webhook. Use when the webhook is no longer needed. Returns empty response on successful deletion (HTTP 204).
Input parameters
The unique identifier of the webhook to be deleted.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_API_QUOTATool to retrieve current API usage quota. Use when monitoring API rate limits to avoid exceeding allowed calls.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_DOMAINTool 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.
Input parameters
Unique identifier for the sending domain
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_DOMAIN_RECIPIENTSTool to list recipients for a domain. Use after obtaining the domain ID to view recipients with optional pagination.
Input parameters
Page number for pagination, must be >= 1
Number of recipients per page (default 25, min 10, max 100)
The ID of the domain to fetch recipients for
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_DOMAINSRetrieve 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.
Input parameters
Page number to retrieve, starting from 1
Number of results per page (default 25, min 10, max 100)
Filter domains by verification status (true for verified only, false for unverified only, omit for all)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_GENERAL_RESOURCESTool to retrieve general API resources and information. Use when you need an overview of all MailerSend endpoints before constructing specific calls.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_IDENTITIESRetrieves 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.
Input parameters
Page number for pagination (starting from 1). Leave empty to get the first page.
Number of results per page (min: 10, max: 100, default: 25). Leave empty for default.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_MESSAGESTool to retrieve a paginated list of sent messages. Use after sending emails to view message logs.
Input parameters
Page number for pagination (starts at 1)
Number of messages per page (max 100)
Filter messages sent on or before this datetime (ISO 8601)
Filter messages sent on or after this datetime (ISO 8601)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_RECIPIENTSTool to retrieve a list of email recipients. Use when you need to list and filter recipients by list ID or search term.
Input parameters
Page number for pagination, starting from 1
Number of results per page (default 25, maximum 100)
Term to search in recipient email address or name
Filter recipients by this mailing list ID
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_SMS_ACTIVITYTool to retrieve SMS activity logs. Use when you need to fetch delivery status and logs of sent SMS messages.
Input parameters
Page number for pagination, starting from 1
Number of results per page (default: 25, min: 10, max: 100)
Filter by message status. Can specify multiple statuses
Filter activities created before this Unix timestamp in UTC (e.g., 1443651141). Must be higher than date_from
Filter activities created after this Unix timestamp in UTC (e.g., 1443651141). Must be lower than date_to
Filter by specific SMS phone number ID
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_SMS_INBOUNDSRetrieve inbound SMS route configurations. Inbound routes define rules for forwarding incoming SMS messages to webhook URLs based on message content filters. Use this action when you need to: - List all configured SMS inbound routes - Filter routes by SMS number or enabled status - Review webhook forwarding configurations and filter rules
Input parameters
Page number for pagination (starts from 1)
Number of results per page (default: 25, min: 10, max: 100)
Filter inbound routes by enabled status (true for enabled, false for disabled)
Filter inbound routes by SMS number ID
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_SMS_MESSAGESRetrieves a paginated list of SMS messages sent through the MailerSend API. Returns message details including sender, recipients, content, status, and timestamps. Use this to review sent SMS messages and track their delivery status. Note: For detailed activity tracking with filters (date ranges, status, phone numbers), use the SMS Activity endpoint instead.
Input parameters
Page number for pagination (must be >= 1)
Number of results per page (min 10, max 100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_SMS_NUMBERSTool to retrieve a paginated list of SMS phone numbers. Use after purchasing numbers to fetch available SMS numbers.
Input parameters
Page number for pagination, starting from 1
Number of SMS numbers per page (range: 10-100, default: 25)
Filter by paused status (true for paused only, false for active only, omit for all)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_SMS_RECIPIENTSTool to retrieve a list of SMS recipients. Use when you need to list and paginate SMS recipients, optionally filtering by SMS number ID and/or recipient status.
Input parameters
Page number to retrieve, starting from 1
Number of recipients per page (minimum 10, maximum 100, default 25)
Filter by recipient status: 'active' or 'opt_out'
Filter recipients by SMS number ID.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_SMTP_USERSTool to retrieve a list of SMTP users. Use when you need to list and paginate SMTP users.
Input parameters
Page number to retrieve, starting from 1
Number of records per page (default 25, maximum 100)
Domain ID to retrieve SMTP users for (required, as SMTP users are always scoped to a domain)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_TEMPLATESRetrieves a paginated list of email templates from your MailerSend account. Use this tool when you need to: - List all available email templates - Filter templates by domain ID - Browse templates with pagination - Check template details like name, type, and creation date Returns template metadata including IDs, names, types, and timestamps. For full template content, use a separate get single template endpoint.
Input parameters
Page number for pagination, starting from 1
Number of templates per page (minimum 10, maximum 100, default 25)
Filter templates by domain ID to retrieve only templates belonging to a specific domain
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_TOKENSRetrieves a paginated list of API tokens associated with your MailerSend account. Returns token details including ID, name, status, creation date, and assigned scopes/permissions. Requires 'tokens_full' scope.
Input parameters
Page number for pagination, starting from 1 (default: 1)
Number of items per page (min=10, max=100, default=25)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_USERSTool to retrieve a list of users associated with your account. Use after authenticating with a valid API token.
Input parameters
Page number for pagination, must be >= 1
Number of users per page (default 25, maximum 100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
MAILERSEND_GET_WEBHOOKSTool to retrieve a list of webhooks. Use when you need to list and paginate all configured webhooks, optionally filtering by domain.
Input parameters
Page number to retrieve, starting from 1
Number of webhooks per page (default 25)
Filter webhooks belonging to this domain
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
No publicly available marketplace agent is found using this tool yet. There are 92 agents privately built on Nagent that already use MailerSend.
Build on Nagent
Connect MailerSend to any Nagent agent in minutes — no API key management, no boilerplate. Just configure and deploy.
The five questions agent builders ask before adopting a new integration.
Open the External Integrations panel inside Nagent (app.nagent.ai/externalIntegration), find MailerSend, and click "Connect Now." You'll authenticate with an API key — Nagent handles credential storage and refresh automatically. Once connected, MailerSend is available to any agent in your workspace.
No. Nagent provides no-code integration for every tool. Once MailerSend is connected, you configure its 23 actions directly in the agent builder UI — no API calls, no boilerplate, no schema management.
Helix — Nagent's agentic agent builder — lets you drop MailerSend steps into any workflow visually. Pick an action (e.g., one of those listed above), fill in the inputs (Helix knows the required vs. optional schema for each parameter), and connect it to upstream/downstream steps. Triggers run as the entry point of an agent, so when a MailerSend event fires, the agent kicks off automatically.
Every MailerSend action and trigger ships with a fully-typed schema — input parameters with name, type, required flag, and description, plus the output payload shape. The schemas are documented in the sections above. Helix uses these schemas to validate your configuration at build time and to type-check the data flowing between steps.
Yes. While MailerSend ships with 23 pre-built transactional email actions, you can layer custom logic around them inside Helix — pre/post-processing steps, conditional branches, retries, or stitching MailerSend together with other connected tools. For deeper customization, talk to our team about Nagent's Agentic AI Lab — forward-deployed engineers who build MailerSend-based workflows tailored to your business.