Mailtrap Email Sending

Instructions

Implementation Reference

• src/tools/sendEmail/sendEmail.ts:1-111 (handler)

  The handler function 'sendEmail' that executes the logic to send an email using the Mailtrap API client. Handles validation, normalization of addresses, and sends the email.
  import { Address, Mail } from "mailtrap"; import { SendMailToolRequest } from "../../types/mailtrap"; import { client } from "../../client"; const { DEFAULT_FROM_EMAIL } = process.env; async function sendEmail({ from, to, subject, text, cc, bcc, category, html, }: SendMailToolRequest): Promise<{ content: any[]; isError?: boolean }> { try { if (!client) { throw new Error("MAILTRAP_API_TOKEN environment variable is required"); } if (!html && !text) { throw new Error("Either HTML or TEXT body is required"); } const fromEmail = from ?? DEFAULT_FROM_EMAIL; if (!fromEmail) { throw new Error( "No 'from' email provided and no 'DEFAULT_FROM_EMAIL' email set" ); } const fromAddress: Address = { email: fromEmail, }; // Handle both single email and array of emails // Normalize inputs: convert to array, trim each email, filter empty strings const normalizedToEmails = (Array.isArray(to) ? to : [to]) .map((email) => email.trim()) .filter((email) => email.length > 0); // Validate that we have at least one valid recipient after normalization if (normalizedToEmails.length === 0) { throw new Error( "No valid recipients provided in 'to' field after normalization" ); } const toAddresses: Address[] = normalizedToEmails.map((email) => ({ email, })); const emailData: Mail = { from: fromAddress, to: toAddresses, subject, text, html, category, }; if (cc && cc.length > 0) { const normalizedCcEmails = cc .map((email) => email.trim()) .filter((email) => email.length > 0); if (normalizedCcEmails.length > 0) { emailData.cc = normalizedCcEmails.map((email) => ({ email })); } } if (bcc && bcc.length > 0) { const normalizedBccEmails = bcc .map((email) => email.trim()) .filter((email) => email.length > 0); if (normalizedBccEmails.length > 0) { emailData.bcc = normalizedBccEmails.map((email) => ({ email })); } } const response = await client.send(emailData); return { content: [ { type: "text", text: `Email sent successfully to ${toAddresses .map((addr) => addr.email) .join(", ")}.\nMessage IDs: ${response.message_ids}\nStatus: ${ response.success ? "Success" : "Failed" }`, }, ], }; } catch (error) { const errorMessage = error instanceof Error ? error.message : String(error); return { content: [ { type: "text", text: `Failed to send email: ${errorMessage}`, }, ], isError: true, }; } } export default sendEmail;
• src/tools/sendEmail/schema.ts:1-76 (schema)

  Defines the JSON schema for validating input parameters to the send-email tool, including from, to, subject, etc., with conditional requirements based on environment.
  const hasDefaultFromEmail = !!process.env.DEFAULT_FROM_EMAIL; const sendEmailSchema = { type: "object", properties: { from: { type: "string", format: "email", description: hasDefaultFromEmail ? "Email address of the sender (optional with default)" : "Email address of the sender", }, to: { oneOf: [ { type: "string", format: "email", description: "Single email address", }, { type: "array", items: { type: "string", format: "email", }, description: "Array of email addresses", }, ], description: "Email address(es) of the recipient(s) - can be a single email or array of emails", }, subject: { type: "string", description: "Email subject line", }, cc: { type: "array", items: { type: "string", format: "email", }, description: "Optional CC recipients", }, bcc: { type: "array", items: { type: "string", format: "email", }, description: "Optional BCC recipients", }, category: { type: "string", description: "Email category for tracking", }, text: { type: "string", description: "Email body text", }, html: { type: "string", description: "Optional HTML version of the email body", }, }, required: ["to", "subject", "category"], additionalProperties: false, }; if (hasDefaultFromEmail) { // Make from optional when default is available sendEmailSchema.required = sendEmailSchema.required.filter( (field: string) => field !== "from" ); } export default sendEmailSchema;
• src/server.ts:36-45 (registration)

  Registers the 'send-email' tool in the tools array used by the MCP server, linking the schema and handler.
  { name: "send-email", description: "Send an email to your recipient email address using Mailtrap Email API. You can send emails to multiple recipients at once.", inputSchema: sendEmailSchema, handler: sendEmail, annotations: { destructiveHint: true, }, },