Can I use templates with the send_transactional_email tool?

Yes, you can specify a `template_id` within the `email_json` body to use pre-defined designs created in your MailerSend account.

How do I filter activity for a specific event like 'opened'?

Use the `list_domain_activity` tool and provide the `params` string with the desired event types (e.g., `event[]=opened`).

Is there a limit to bulk email requests?

The `send_bulk_transactional_emails` tool supports up to 500 email objects per single request as per MailerSend API limits.

MailerSend MCP Server for CrewAI 10 tools — connect in under 2 minutes

Name: MailerSend
Availability: InStock
Author: Vinkius

docs.crewai.com/mcp/overview

Built by Vinkius GDPR 10 Tools Framework

Connect your CrewAI agents to MailerSend through Vinkius, pass the Edge URL in the `mcps` parameter and every MailerSend tool is auto-discovered at runtime. No credentials to manage, no infrastructure to maintain.

Get MCP Server for AI Agents

ASK AI ABOUT THIS MCP SERVER

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Vinkius supports streamable HTTP and SSE.

python

from crewai import Agent, Task, Crew

agent = Agent(
    role="MailerSend Specialist",
    goal="Help users interact with MailerSend effectively",
    backstory=(
        "You are an expert at leveraging MailerSend tools "
        "for automation and data analysis."
    ),
    # Your Vinkius token. get it at cloud.vinkius.com
    mcps=["https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp"],
)

task = Task(
    description=(
        "Explore all available tools in MailerSend "
        "and summarize their capabilities."
    ),
    agent=agent,
    expected_output=(
        "A detailed summary of 10 available tools "
        "and what they can do."
    ),
)

crew = Crew(agents=[agent], tasks=[task])
result = crew.kickoff()
print(result)

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Stream every event to Splunk, Datadog, or your own webhook in real-time

* Every MCP server runs on Vinkius-managed infrastructure inside AWS - a purpose-built runtime with per-request V8 isolates, Ed25519 signed audit chains, and sub-40ms cold starts optimized for native MCP execution. See our infrastructure

About MailerSend MCP Server

Connect your MailerSend account to any AI agent to automate your transactional messaging and domain management. This MCP server enables your agent to send single or bulk emails, monitor domain verification, and track email activity directly from natural language interfaces.

When paired with CrewAI, MailerSend becomes a first-class tool in your multi-agent workflows. Each agent in the crew can call MailerSend tools autonomously, one agent queries data, another analyzes results, a third compiles reports, all orchestrated through Vinkius with zero configuration overhead.

What you can do

Email Delivery — Send transactional emails instantly with support for HTML, text, and templates
Bulk Operations — Send up to 500 emails in a single batch request for high-volume communications
Domain Oversight — List sender domains, retrieve DNS settings, and trigger ownership verification checks
Recipient Management — List and query recipients from your account database to track engagement
Activity Auditing — Access real-time logs of email events (sent, delivered, opened, clicked) for any domain
Message Insight — Retrieve complete metadata and lifecycle history for individual sent messages

The MailerSend MCP Server exposes 10 tools through the Vinkius. Connect it to CrewAI in under two minutes — no API keys to rotate, no infrastructure to provision, no vendor lock-in. Your configuration, your data, your control.

How to Connect MailerSend to CrewAI via MCP

Follow these steps to integrate the MailerSend MCP Server with CrewAI.

Install CrewAI

Run pip install crewai

Replace the token

Replace [YOUR_TOKEN_HERE] with your Vinkius token from cloud.vinkius.com

Customize the agent

Adjust the role, goal, and backstory to fit your use case

Run the crew

Run python crew.py. CrewAI auto-discovers 10 tools from MailerSend

Why Use CrewAI with the MailerSend MCP Server

CrewAI Multi-Agent Orchestration Framework provides unique advantages when paired with MailerSend through the Model Context Protocol.

Multi-agent collaboration lets you decompose complex workflows into specialized roles, one agent researches, another analyzes, a third generates reports, each with access to MCP tools

CrewAI's native MCP integration requires zero adapter code: pass Vinkius Edge URL directly in the `mcps` parameter and agents auto-discover every available tool at runtime

Built-in task delegation and shared memory mean agents can pass context between steps without manual state management, enabling multi-hop reasoning across tool calls

Sequential and hierarchical crew patterns map naturally to real-world workflows: enumerate subdomains → analyze DNS history → check WHOIS records → compile findings into actionable reports

MailerSend + CrewAI Use Cases

Practical scenarios where CrewAI combined with the MailerSend MCP Server delivers measurable value.

Automated multi-step research: a reconnaissance agent queries MailerSend for raw data, then a second analyst agent cross-references findings and flags anomalies. all without human handoff

Scheduled intelligence reports: set up a crew that periodically queries MailerSend, analyzes trends over time, and generates executive briefings in markdown or PDF format

Multi-source enrichment pipelines: chain MailerSend tools with other MCP servers in the same crew, letting agents correlate data across multiple providers in a single workflow

Compliance and audit automation: a compliance agent queries MailerSend against predefined policy rules, generates deviation reports, and routes findings to the appropriate team

MailerSend MCP Tools for CrewAI (10)

These 10 tools become available when you connect MailerSend to CrewAI via MCP:

get_recipient_details

Get details for a specific recipient

get_sender_domain_details

Get details for a specific domain

get_sent_message_details

Get details for a specific sent message

list_domain_activity

List email activity for a specific domain

list_email_recipients

List all recipients in the account database

list_sender_domains

List all verified and unverified sender domains

list_sent_messages

List all sent email messages

send_bulk_transactional_emails

Send multiple transactional emails in one batch

send_transactional_email

Requires a JSON body with sender, recipient, and content (text/html) or template ID. Send a single transactional email

verify_sender_domain

Trigger a DNS verification check for a domain

Example Prompts for MailerSend in CrewAI

Ready-to-use prompts you can give your CrewAI agent to start working with MailerSend immediately.

"Send a transactional email to 'user@example.com' with subject 'Welcome' and body 'Hello!'."

"List all active sender domains in my account."

"Show recent opened events for domain ID '98765'."

Troubleshooting MailerSend MCP Server with CrewAI

Common issues when connecting MailerSend to CrewAI through the Vinkius, and how to resolve them.

MCP tools not discovered

Ensure the Edge URL is correct. CrewAI connects lazily when the crew starts. check console output.

Agent not using tools

Make the task description specific. Instead of "do something", say "Use the available tools to list contacts".

Timeout errors

CrewAI has a 10s connection timeout by default. Ensure your network can reach the Edge URL.

Rate limiting or 429 errors

Vinkius enforces per-token rate limits. Check your subscription tier and request quota in the dashboard. Upgrade if you need higher throughput.

MailerSend + CrewAI FAQ

Common questions about integrating MailerSend MCP Server with CrewAI.

How does CrewAI discover and connect to MCP tools?

CrewAI connects to MCP servers lazily. when the crew starts, each agent resolves its MCP URLs and fetches the tool catalog via the standard tools/list method. This means tools are always fresh and reflect the server's current capabilities. No tool schemas need to be hardcoded.

Can different agents in the same crew use different MCP servers?

Yes. Each agent has its own mcps list, so you can assign specific servers to specific roles. For example, a reconnaissance agent might use a domain intelligence server while an analysis agent uses a vulnerability database server.

What happens when an MCP tool call fails during a crew run?

CrewAI wraps tool failures as context for the agent. The LLM receives the error message and can decide to retry with different parameters, fall back to a different tool, or mark the task as partially complete. This resilience is critical for production workflows.

Can CrewAI agents call multiple MCP tools in parallel?

CrewAI agents execute tool calls sequentially within a single reasoning step. However, you can run multiple agents in parallel using process=Process.parallel, each calling different MCP tools concurrently. This is ideal for workflows where separate data sources need to be queried simultaneously.

Can I run CrewAI crews on a schedule (cron)?

Yes. CrewAI crews are standard Python scripts, so you can invoke them via cron, Airflow, Celery, or any task scheduler. The crew.kickoff() method runs synchronously by default, making it straightforward to integrate into existing pipelines.