Bring Transactional Email
to CrewAI
Create your Vinkius account to connect MailerSend to CrewAI and start using all 10 AI tools in minutes. Fully managed, enterprise secure, and ready to use without writing a single line of code. No hosting, no server setup — just connect and start using.
Compatible with every major AI agent and IDE
What is the 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.
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
How it works
- Subscribe to this server
- Enter your MailerSend API Token
- Start managing your transactional emails from Claude, Cursor, or any MCP-compatible client
Who is this for?
- Developers — Quickly test email sending and verify domain configurations from your IDE
- Operations Teams — Monitor email delivery performance and audit activities via natural language commands
- Marketing Engineers — Automate the synchronization of recipient data and track campaign-level interactions
Built-in capabilities (10)
Get details for a specific recipient
Get details for a specific domain
Get details for a specific sent message
List email activity for a specific domain
List all recipients in the account database
List all verified and unverified sender domains
List all sent email messages
Send multiple transactional emails in one batch
Requires a JSON body with sender, recipient, and content (text/html) or template ID. Send a single transactional email
Trigger a DNS verification check for a domain
Why CrewAI?
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.
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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
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CrewAI's native MCP integration requires zero adapter code: pass Vinkius Edge URL directly in the
mcpsparameter 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
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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 in CrewAI
Why run MailerSend with Vinkius?
The MailerSend connection runs on our fully managed, secure cloud infrastructure. We handle the hosting, maintenance, and security so you don't have to deal with servers or code. All 10 tools are ready to work instantly without any complex setup.
You stay in complete control of your data. Your AI only accesses the information you approve, keeping your sensitive passwords and private details completely safe. Plus, with automatic optimizations, your AI works faster and more efficiently.

* Every connection is hosted and maintained by Vinkius. We handle the security, updates, and infrastructure so you don't have to write code or manage servers. See our infrastructure
Over 4,000 integrations ready for AI agents
Explore a vast library of pre-built integrations, optimized and ready to deploy.
Connect securely in under 30 seconds
Generate tokens to authenticate and link external services in a single step.
Complete visibility into every agent action
Audit live requests, latency, success rates, and active security compliance policies.
Optimize spending and track token ROI
Analyze real-time token consumption and cost metrics detailed by connection.




Explore our live AI Agents Analytics dashboard to see it all working
This dashboard is included when you connect MailerSend using Vinkius. You will never be left in the dark about what your AI agents are doing with your tools.
MailerSend and 4,000+ other AI tools. No hosting, no code, ready to use.
Professionals who connect MailerSend to CrewAI through Vinkius don't need to write code, manage servers, or worry about security. Everything is pre-configured, secure, and runs automatically in the background.
Raw MCP | Vinkius | |
|---|---|---|
| Ready-to-use MCPs | Find and configure each manually | 4,000+ MCPs ready to use |
| Connection Setup | Manual coding & server setup | 1-click instant connection |
| Server Hosting | You host it yourself (needs 24/7 uptime) | 100% hosted & managed by Vinkius |
| Security & Privacy | Stored in plaintext config files | Bank-grade encrypted vault |
| Activity Visibility | Blind execution (no logs or tracking) | Live dashboard with real-time logs |
| Cost Control | Runaway AI token spend risk | Automatic budget limits |
| Revoking Access | Must delete files or code to stop | 1-click disconnect button |
How Vinkius secures
MailerSend for CrewAI
Every request between CrewAI and MailerSend is protected by our secure gateway. We automatically keep your sensitive data private, prevent unauthorized access, and let you disconnect instantly at any time.
Frequently asked questions
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.
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.
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.
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