--- title: "Connect MailerSend to Lettr - APIANT.ai" description: "When \"Email Is Clicked Through\" fires in MailerSend, your agent runs \"Add contact\" in Lettr." canonical: "https://apiant.ai/connect/mailersend-to-lettr" --- # Connect MailerSend to Lettr When **Email Is Clicked Through** fires in [MailerSend](https://apiant.ai/connections/mailersend), your agent runs **Add contact** in [Lettr](https://apiant.ai/connections/lettr). Describe the whole flow and it is built, tested on every scenario and kept running. MailerSend **11** triggers MailerSend **1** action Lettr **11** actions What the catalog holds today. Ask for anything missing and your agent reads the API documentation and adds it. ## What do you want MailerSend and Lettr to do together? Give your AI client this address. `https://mcp.apiant.ai` One connection does both: ask your client to act in an app once, or have it build an automation that keeps running. Any client that takes a remote MCP server. Nothing to install. Create your free account, then sign in once in your browser. ### Set it up in your client ### Claude Code Run this in the directory you want to work in. `claude mcp add --transport http -s project apiant-ai https://mcp.apiant.ai` Start Claude Code there, approve the server, and sign in in the browser page it opens. [Claude Code guide (opens in a new tab)](https://apiant.ai/docs/mcp/claude-code) ### Claude, web and desktop Open Customize, then Connectors, then Add custom connector, and paste the address. On Team and Enterprise an owner adds it first. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) ### Cursor Add the address to your MCP configuration as a server URL. Cursor signs you in in your browser. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) ### Zed Open Settings, then AI, then MCP Servers, then Add Server, then Add Remote Server. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) ### Codex and the ChatGPT desktop app Open Settings, then MCP servers, then Add server, and choose Streamable HTTP. From the terminal, Codex takes the address with its own add command and then signs you in. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) ### Any other MCP client Paste the address where the client asks for a remote MCP server URL, and name the server apiant-ai where it lets you. APIANT's skills reach the client over the same connection. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) Example flows ## What MailerSend can start in Lettr - When **Email Is Clicked Through** in MailerSend then **Add contact** in Lettr - When **Email Is Delivered** in MailerSend then **Add contact to list** in Lettr Starting points drawn from the triggers and actions in the catalog today. Describe the flow you need, at any depth, and your agent builds it and tests every scenario before it ships. Everything your agent can do with MailerSend and Lettr ## Triggers and actions 11 triggers · 12 actions - Trigger **Email Is Clicked Through** Triggers when the recipient clicks on a link. - Trigger **Email Is Delivered** Triggers when an email is delivered. - Trigger **Email Is Hard Bounced** Triggers when an email is hard bounced. - Trigger **Email Is Opened** Triggers when an email is opened. - Trigger **Email Is Reported as Spam** Triggers when an email is reported as spam. - Trigger **Email Is Sent** Triggers when an email is sent. - Trigger **Email Is Soft Bounced** Triggers when an email is soft bounced. - Trigger **Recipient Has Unsubscribed** Triggers when a recipient unsubscribes from your mailing activity. - Trigger **SMS Delivery Failed** Triggers when SMS failed to deliver. - Trigger **SMS Is Delivered** Triggers when SMS is delivered. - Trigger **SMS Is Sent** Triggers when SMS is sent. - Action **Send an Email** Send an email via your MailerSend account. - Action **Add audience list** Creates a new audience list in Lettr with the given name and returns the created list. - Action **Add contact** Adds a new contact to your Lettr audience, optionally placing it on a list, setting custom properties, and sending a double opt-in confirmation email. - Action **Add contact to list** Adds an existing contact to one of your audience lists. Succeeds whether the contact was newly added or was already on the list. - Action **Add template** Creates a new email template in Lettr from HTML or Topol editor JSON content, and publishes its first version with the merge tags found in the content. - Action **Delete contact** Permanently deletes a contact from your Lettr audience. - Action **Get contact** Returns a single audience contact, including its subscription status, custom properties, lists and topics. - Action **Get template** Returns a single email template by its slug, including its HTML, editor content, purpose, status and version details. - Action **List audience lists** Returns all audience lists in your Lettr team, with each list's name and contact count. - Action **List contacts** Returns the contacts in your Lettr audience, optionally narrowed by a search term, subscription status, list or segment. - Action **List templates** Returns the email templates in a Lettr project, optionally limited to one folder or to transactional or campaign templates. - Action **Update contact** Updates an existing contact in your Lettr audience, changing its email address, subscription status or custom properties. Fields left blank are not changed. ## Each app on its own - [ **MailerSend** MailerSend is a powerful transactional email system built for developers but designed so non-tech teams can...](https://apiant.ai/connections/mailersend) - [ **Lettr** Lettr is a email API for artisans, send transactional emails using HTML or stored templates.](https://apiant.ai/connections/lettr) Reviews ## What our customers say ## More from MailerSend - [ **MailerSend to Giphy** Giphy is the best way to search, share, and discover GIFs on the Internet.](https://apiant.ai/connect/mailersend-to-giphy) - [ **MailerSend to Poplar** Poplar is a web platform for programmatically print and mail.](https://apiant.ai/connect/mailersend-to-poplar) - [ **MailerSend to Salesforce** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/mailersend-to-salesforce) - [ **MailerSend to Slack** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/mailersend-to-slack) - [ **MailerSend to Stripe** Stripe is a payment processing platform for online businesses.](https://apiant.ai/connect/mailersend-to-stripe) - [ **MailerSend to Shopify** Shopify is a commerce platform for online stores and retail point-of-sale.](https://apiant.ai/connect/mailersend-to-shopify) ## More into Lettr - [ **HubSpot to Lettr** HubSpot is your all-in-one stop for all of your marketing software needs.](https://apiant.ai/connect/hubspot-to-lettr) - [ **Salesforce to Lettr** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/salesforce-to-lettr) - [ **Slack to Lettr** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/slack-to-lettr) - [ **Google Sheets to Lettr** Google Sheets](https://apiant.ai/connect/google-sheets-to-lettr) - [ **Gmail to Lettr** Gmail is Google’s email service, featuring spam protection, search functions, and seamless integration with...](https://apiant.ai/connect/gmail-to-lettr) - [ **Google Calendar to Lettr** Google Calendar is a time management tool providing scheduling features, event reminders, and integration...](https://apiant.ai/connect/google-calendar-to-lettr) Questions ## MailerSend and Lettr, answered ### ### What can start an automation from MailerSend? Any of MailerSend's 11 triggers in the catalog, including Email Is Clicked Through, Email Is Delivered, Email Is Hard Bounced and Email Is Opened. Describe the moment in plain language and your agent picks the right one. ### ### What can your agent do in Lettr when something happens in MailerSend? Any of Lettr's 11 actions, including Update contact, Add audience list, Add contact and Add contact to list. Your agent maps the data both ways and tests every scenario before it ships. ### ### Can it also run from Lettr to MailerSend? Lettr has no triggers in the catalog today, so automations start in MailerSend. If you need the other direction, ask: your agent reads Lettr's API documentation and adds it. ### ### Do I have to build a connector for MailerSend or Lettr? No. Both are in the catalog with their triggers and actions. You describe the automation; your agent builds it, tests every scenario and keeps it running. ### ### Can my AI client use MailerSend and Lettr without building an automation? Yes. With your AI client connected to APIANT, ask it to do something in either app once and it runs that action on the spot. Ask for an automation and your agent builds it, tests every scenario and keeps it running. One connection covers both. ### ### What happens when something fails? Your agent works that out for you. It plans the failure paths along with the happy path, then tests every scenario before it ships. ### ### Is there a free plan? Yes. Every plan includes the agent, including free, and building from your own AI client spends no assistant credits.