--- title: "Connect MailUp to Lettr - APIANT.ai" description: "When \"New Email Message in List\" fires in MailUp, your agent runs \"Add contact\" in Lettr." canonical: "https://apiant.ai/connect/mailup-to-lettr" --- # Connect MailUp to Lettr When **New Email Message in List** fires in [MailUp](https://apiant.ai/connections/mailup), 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. MailUp **4** triggers MailUp **25** actions 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 MailUp 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 MailUp can start in Lettr - When **New Email Message in List** in MailUp then **Add contact** in Lettr - When **New Group** in MailUp 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 MailUp and Lettr ## Triggers and actions 4 triggers · 36 actions - Trigger **New Email Message in List** A new email message was created in the list. MailUp is a multi-list environment and messages are list-specific. - Trigger **New Group** New group added to the specified list. MailUp is a multi-list environment and groups are list-specific. - Trigger **New Recipient Subscribed** There is a new subscriber in the specified list. MailUp is a multi-list environment. - Trigger **New Recipient Unsubscribed** A recipient unsubscribed from the specified list. MailUp is a multi-list environment. - Action **Add list** Create a new list. POST Console/List - Action **Add Recipient to Group** Add recipient to the specified group on the list. - Action **Add Recipient to List** Adds a new recipient to the specified list as a subscriber. - Action **Create New Email Message** Create a new email message on the specified list. - Action **Create New Group** Add a new group to the specified list. MailUp is a multi-list environment. - Action **Delete email message** Delete an email message. DELETE Console/List/{id_List}/Email/{id_Message} - Action **Delete group** Delete a group in a list. DELETE Console/List/{id_List}/Group/{id_Group} - Action **Delete list** Delete a list. DELETE Console/List/{id_List} - Action **Get email message** Retrieve email message details. GET Console/List/{id_List}/Email/{id_Message} - Action **Get list** Retrieve list details by id. GET Console/List/{id_List} - Action **List email messages** Retrieve email messages of a list. GET Console/List/{id_List}/Emails - Action **List Email Message Sendings** lists the sendings (send tasks, with recipients count and status) created for an email message. - Action **List Group Recipients** Lists the recipients in a MailUp group (GET Console/Group/{id_group}/Recipients), with id, email, name and personal data fields. - Action **List groups** Retrieve groups of a list. GET Console/List/{id_List}/Groups - Action **List lists** Retrieve the console's lists. GET Console/List on services.mailup.com/API/v1.1/Rest/ConsoleService.svc - Action **List subscribed recipients** Retrieve subscribed recipients of a list. GET Console/List/{id_List}/Recipients/Subscribed - Action **Remove recipient from group** Unsubscribe a recipient from a group. DELETE Console/Group/{id_Group}/Unsubscribe/{id_Recipient} - Action **Remove Recipient From List** This method unsubscribe the given recipient from the specified list. - Action **Send Message to Email Address** Sends the specified message (previously created in MailUp in the specified List) to the email address specified. - Action **Send Message to Group** Send a message to a predefined group in the specified list. - Action **Send message to list** Send an email message to all recipients of a list. POST Console/List/{id_List}/Email/{id_Message}/Send - Action **Unsubscribe recipient from list** Unsubscribe a recipient from a list. DELETE Console/List/{id_List}/Unsubscribe/{id_Recipient} - Action **Update email message** Modify an email message. PUT Console/List/{id_List}/Email/{id_Message} - Action **Update group** Modify a group in a list. PUT Console/List/{id_List}/Group/{id_Group} - Action **Update list** Modify details of a list. PUT Console/List/{id_List} - 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 - [ **MailUp** MailUp is your complete email delivery solution.](https://apiant.ai/connections/mailup) - [ **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 MailUp - [ **MailUp to SendPulse** SendPulse is an Integrated messaging platform providing user communication on all devices with Emails, SMS...](https://apiant.ai/connect/mailup-to-sendpulse) - [ **MailUp to Salesforce** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/mailup-to-salesforce) - [ **MailUp to Slack** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/mailup-to-slack) - [ **MailUp to Stripe** Stripe is a payment processing platform for online businesses.](https://apiant.ai/connect/mailup-to-stripe) - [ **MailUp to Shopify** Shopify is a commerce platform for online stores and retail point-of-sale.](https://apiant.ai/connect/mailup-to-shopify) - [ **MailUp to QuickBooks Online** QuickBooks Online accounting — manage customers, invoices, bills, payments, vendors, expenses, and more via...](https://apiant.ai/connect/mailup-to-quickbooks-online) ## 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 ## MailUp and Lettr, answered ### ### What can start an automation from MailUp? Any of MailUp's 4 triggers in the catalog, including New Email Message in List, New Group, New Recipient Subscribed and New Recipient Unsubscribed. Describe the moment in plain language and your agent picks the right one. ### ### What can your agent do in Lettr when something happens in MailUp? 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 MailUp? Lettr has no triggers in the catalog today, so automations start in MailUp. 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 MailUp 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 MailUp 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.