Advertising & Marketing · Lettr + Claude
Lettr MCP with Claude: Automate Product Email and Customer Messaging
The short answer
Claude works with Lettr through the Model Context Protocol (MCP), a secure standard that lets Claude use the tool with permissions you control. Once connected with an API key, Claude can send transactional emails, manage templates, update audiences and track campaigns based on natural language instructions from your team.
What is Lettr?
Lettr is an email and messaging platform used to send transactional and marketing messages from one place. It handles transactional delivery for product emails such as receipts, password resets and account notices. It also supports message templates, audience lists, campaigns, sending domains and webhooks that notify other systems when events happen. Product teams, marketing teams and customer operations staff typically use it to keep customer communication reliable and organised.
How Claude connects to Lettr through MCP
The Model Context Protocol (MCP) is an open standard that lets Claude securely use other software. Think of it as a universal adapter between Claude and a tool like Lettr. It gives Claude a defined set of actions it may take, and nothing beyond that.
Once connected, Claude can typically read templates, look at audiences, check campaign activity and send transactional emails when asked. A team member could ask Claude to draft a shipping confirmation template or summarise how a recent campaign performed, and Claude carries out those steps inside Lettr.
Access is controlled by the API key the organisation provides, which we configure with least-privilege permissions. Consequential actions, such as sending to a large audience, can require a person to approve first. Audit logs record what Claude did, so your team stays in charge throughout.
What you can automate
Transactional receipts and notices
Claude can send order confirmations, payment receipts and account notices through Lettr when your application triggers them. A support lead can ask Claude to resend a receipt to a customer, and Claude checks the template and sends it, with the action logged for later review.
Template management
Product and marketing teams often need small wording changes across many templates. Claude can help list existing templates, propose revised copy and update the draft for review. A person approves the change before it goes live, which saves hours of manual editing.
Audience updates
Keeping audience lists accurate matters for good deliverability and compliance. Claude can add, update or remove contacts in named audiences based on rules your team sets, such as moving customers who have changed plans into the correct group.
Campaign tracking and reporting
Marketing managers can ask Claude for a plain summary of how a campaign is performing. Claude reads campaign activity from Lettr and produces a short report covering delivery and engagement, which helps teams decide what to send next.
Domain and webhook checks
Operations staff can ask Claude to review sending domains and webhook settings during a release. Claude lists the current configuration and flags anything that looks out of date, so a technical owner can make the final change.
An end-to-end workflow: Order dispatch notifications with CRM logging
TriggerYour warehouse system marks an order as dispatched.
The order event reaches Claude, which checks the customer record in your CRM.
Claude selects the correct shipping template in Lettr and fills in the tracking details.
Claude sends the transactional email through Lettr and confirms delivery has been accepted.
Claude records the send against the customer in the CRM so the support team can see it.
Any failed sends are queued and flagged to the operations team for a person to review.
OutcomeCustomers receive dispatch emails promptly, support staff see a complete message history, and failed sends are caught early rather than going unnoticed.
How we set it up
Free automation audit
We review how your team sends customer email today and identify the workflows worth automating with Lettr and Claude. You receive a short written plan at no cost.
Secure connection
We connect Claude to Lettr using an API key, stored securely and scoped to the permissions your workflows need. No broader access is granted than necessary.
Workflow design
We design the end-to-end process across Lettr and your other systems, such as Microsoft 365, your CRM or your ticketing tool. People approve any consequential actions before they run.
Testing with real cases
We test the workflow against past real examples, such as previous orders or campaigns, to confirm the output is correct before anything goes live.
Launch and team training
We launch with monitoring and audit logs in place, then train your team on how to ask Claude for tasks, review results and handle exceptions.
Who benefits
- Product managers
- Reliable transactional emails tied to product events, with fewer manual steps to change wording or resend messages.
- Marketing managers
- Faster template updates and clear campaign summaries without digging through dashboards.
- Customer support leads
- Quick resends of receipts and notices, and a visible record of what each customer was sent.
- Operations and IT heads
- Controlled access through API keys, audit logs and a clear view of domain and webhook settings.
Security and control
- API keys are stored securely and scoped to the minimum permissions each workflow needs.
- People approve consequential actions, such as sends to large audiences or changes to live templates.
- Audit logs record what Claude did in Lettr, supporting review and accountability.
- Workflows are tested against real past cases before launch, and monitored afterwards.
- Customer data is handled in line with your own consent and data policies.
For teams in the US, UK, India and the Middle East
Organisations in the United States and the United Kingdom can align Lettr workflows with their existing email consent and privacy rules. In India, workflows can be designed to meet the Digital Personal Data Protection Act, 2023. Businesses in the UAE and Saudi Arabia can meet local data protection requirements. Claude applications we build can be hosted in India, the United States, the United Kingdom or the European Union, so the hosting region is chosen to meet your requirements.
Learn more about Claude and MCP
Anthropic's AI model and assistant.
Secure links between Claude and business tools.
How engineers build and change software with Claude.
Hosted agents that run multi-step work.
The open standard Claude uses to connect to tools.
Frequently asked questions
What does the Lettr MCP server do?
The Lettr MCP server acts as a secure bridge between Claude and your Lettr account. It lets Claude send transactional emails, manage templates, update audiences and check campaign activity using the permissions you grant. It does not give Claude access beyond the actions you have approved for your workflows.
Is connecting Claude to Lettr secure?
Yes, when it is set up correctly. Access uses an API key that we store securely and scope to the minimum permissions needed. Consequential actions can require human approval, and audit logs record activity so your team can review what happened at any time.
What can Claude do with Lettr?
Once connected, Claude can typically send transactional emails, draft and update templates, add or change contacts in audiences, review campaign performance and check sending domains and webhook settings. The exact actions depend on the permissions your team configures.
How long does setup take?
Simple connections can be ready quickly, but a complete workflow usually takes a few weeks. This includes the free audit, secure connection, design, testing with real cases and team training. We confirm the timeline during the audit based on your workflows.
Which permissions or access are needed?
You need an API key from your Lettr account with permissions suited to the workflows you plan. Generally, read access covers reporting and template review, while send and update access is needed for automated messaging. We recommend starting with the narrowest set and widening it only when needed.