MCP Mailtrap Server

Instructions

Implementation Reference

• src/tools/sandbox/showSandboxEmailMessage.ts:4-125 (handler)

  The main handler function that fetches the sandbox email message details, HTML, and text content using Mailtrap API, formats them, and returns as MCP content blocks.

  async function showEmailMessage({
    message_id,
  }: ShowEmailMessageRequest): Promise<{ content: any[]; isError?: boolean }> {
    try {
      const { MAILTRAP_TEST_INBOX_ID } = process.env;
  
      if (!MAILTRAP_TEST_INBOX_ID) {
        throw new Error(
          "MAILTRAP_TEST_INBOX_ID environment variable is required for sandbox mode"
        );
      }
  
      // Check if sandbox client is available
      if (!sandboxClient) {
        throw new Error(
          "Sandbox client is not available. Please set MAILTRAP_TEST_INBOX_ID environment variable."
        );
      }
  
      const inboxId = Number(MAILTRAP_TEST_INBOX_ID);
  
      // Get message details
      // The showEmailMessage method takes inboxId and messageId
      const message = await sandboxClient.testing.messages.showEmailMessage(
        inboxId,
        message_id
      );
  
      if (!message) {
        return {
          content: [
            {
              type: "text",
              text: `Message with ID ${message_id} not found.`,
            },
          ],
          isError: true,
        };
      }
  
      // Get HTML and text content
      let htmlContent = "";
      let textContent = "";
  
      try {
        htmlContent = await sandboxClient.testing.messages.getHtmlMessage(
          inboxId,
          message_id
        );
      } catch (error) {
        // HTML might not be available
        console.warn("Could not retrieve HTML content:", error);
      }
  
      try {
        textContent = await sandboxClient.testing.messages.getTextMessage(
          inboxId,
          message_id
        );
      } catch (error) {
        // Text might not be available
        console.warn("Could not retrieve text content:", error);
      }
  
      const messageDetails = [
        `Message ID: ${message.id}`,
        `From: ${message.from_email}`,
        `To: ${message.to_email}`,
        `Subject: ${message.subject}`,
        `Sent: ${message.sent_at}`,
        `Read: ${message.is_read ? "Yes" : "No"}`,
        message.html_body_size
          ? `HTML Size: ${message.html_body_size} bytes`
          : "",
        message.text_body_size
          ? `Text Size: ${message.text_body_size} bytes`
          : "",
        message.email_size ? `Total Size: ${message.email_size} bytes` : "",
      ]
        .filter(Boolean)
        .join("\n");
  
      let contentText = `Sandbox Email Message Details:\n\n${messageDetails}`;
  
      if (htmlContent) {
        contentText += `\n\n--- HTML Content ---\n${htmlContent}`;
      }
  
      if (textContent) {
        contentText += `\n\n--- Text Content ---\n${textContent}`;
      }
  
      if (!htmlContent && !textContent) {
        contentText += "\n\nNote: Message body content could not be retrieved.";
      }
  
      return {
        content: [
          {
            type: "text",
            text: contentText,
          },
        ],
      };
    } catch (error) {
      console.error("Error showing sandbox email message:", error);
  
      const errorMessage = error instanceof Error ? error.message : String(error);
  
      return {
        content: [
          {
            type: "text",
            text: `Failed to show sandbox email message: ${errorMessage}`,
          },
        ],
        isError: true,
      };
    }
  }
  
  export default showEmailMessage;

• src/tools/sandbox/schemas/showEmailMessage.ts:1-13 (schema)

  JSON Schema defining the input parameters for the tool, requiring a numeric message_id.

  const showEmailMessageSchema = {
    type: "object",
    properties: {
      message_id: {
        type: "number",
        description: "ID of the sandbox email message to retrieve",
      },
    },
    required: ["message_id"],
    additionalProperties: false,
  };
  
  export default showEmailMessageSchema;

• src/server.ts:98-104 (registration)

  Registration of the tool in the server's tools array, specifying name, description, input schema, and handler function.

  {
    name: "show-sandbox-email-message",
    description:
      "Show sandbox email message details and content from the sandbox test inbox",
    inputSchema: showEmailMessageSchema,
    handler: showEmailMessage,
  },