Mail MCP Tool

Implementation Reference

• src/tools/mail-service.ts:156-178 (handler)

  Core implementation of sendMail in MailService class using nodemailer Transporter to send email with SMTP.

  async sendMail(mailInfo: MailInfo): Promise<{ success: boolean; messageId?: string; error?: string }> {
    try {
      const mailOptions = {
        from: {
          name: this.config.defaults.fromName,
          address: this.config.defaults.fromEmail,
        },
        to: mailInfo.to,
        cc: mailInfo.cc,
        bcc: mailInfo.bcc,
        subject: mailInfo.subject,
        text: mailInfo.text,
        html: mailInfo.html,
        attachments: mailInfo.attachments,
      };
  
      const info = await this.smtpTransporter.sendMail(mailOptions);
      return { success: true, messageId: info.messageId };
    } catch (error) {
      console.error('发送邮件错误:', error);
      return { success: false, error: error instanceof Error ? error.message : String(error) };
    }
  }

• src/tools/mail.ts:224-310 (registration)

  MCP tool registration for 'sendMail' using McpServer.tool(), including Zod input schema and async execution handler that prepares MailInfo and calls MailService.sendMail.

  this.server.tool(
    "sendMail",
    {
      to: z.array(z.string()),
      cc: z.string().or(z.array(z.string())).optional(),
      bcc: z.string().or(z.array(z.string())).optional(),
      subject: z.string(),
      text: z.string().optional(),
      html: z.string().optional(),
      useHtml: z.boolean().default(false),
      attachments: z.array(
        z.object({
          filename: z.string(),
          content: z.union([z.string(), z.instanceof(Buffer)]),
          contentType: z.string().optional()
        })
      ).optional()
    },
    async (params) => {
      try {
        // 检查内容是否提供
        if (!params.text && !params.html) {
          return {
            content: [
              { type: "text", text: `邮件内容不能为空，请提供text或html参数。` }
            ]
          };
        }
        
        // 如果指定使用HTML但没有提供HTML内容，自动转换
        if (params.useHtml && !params.html && params.text) {
          // 简单转换文本为HTML
          params.html = params.text
            .split('\n')
            .map(line => `<p>${line}</p>`)
            .join('');
        }
        
        // 处理收件人信息，确保to字段一定存在
        const to = params.to;
        
        const mailInfo: MailInfo = {
          to: to,
          subject: params.subject,
          attachments: params.attachments
        };
        
        // 处理抄送和密送信息
        if (params.cc) {
          mailInfo.cc = typeof params.cc === 'string' ? params.cc : params.cc;
        }
        
        if (params.bcc) {
          mailInfo.bcc = typeof params.bcc === 'string' ? params.bcc : params.bcc;
        }
        
        // 设置邮件内容
        if (params.html || (params.useHtml && params.text)) {
          mailInfo.html = params.html || params.text?.split('\n').map(line => `<p>${line}</p>`).join('');
        } else {
          mailInfo.text = params.text;
        }
        
        const result = await this.mailService.sendMail(mailInfo);
        
        if (result.success) {
          return {
            content: [
              { type: "text", text: `邮件发送成功，消息ID: ${result.messageId}\n\n提示：如果需要等待对方回复，可以使用 waitForReply 工具。` }
            ]
          };
        } else {
          return {
            content: [
              { type: "text", text: `邮件发送失败: ${result.error}` }
            ]
          };
        }
      } catch (error) {
        return {
          content: [
            { type: "text", text: `发送邮件时发生错误: ${error instanceof Error ? error.message : String(error)}` }
          ]
        };
      }
    }
  );

• src/tools/mail.ts:226-240 (schema)

  Zod schema for sendMail tool input parameters, defining structure for recipients, subject, content, and attachments.

  {
    to: z.array(z.string()),
    cc: z.string().or(z.array(z.string())).optional(),
    bcc: z.string().or(z.array(z.string())).optional(),
    subject: z.string(),
    text: z.string().optional(),
    html: z.string().optional(),
    useHtml: z.boolean().default(false),
    attachments: z.array(
      z.object({
        filename: z.string(),
        content: z.union([z.string(), z.instanceof(Buffer)]),
        contentType: z.string().optional()
      })
    ).optional()

• src/tools/mail-service.ts:34-46 (schema)

  TypeScript interface MailInfo defining the input structure passed to the sendMail method.

  export interface MailInfo {
    to: string | string[];
    cc?: string | string[];
    bcc?: string | string[];
    subject: string;
    text?: string;
    html?: string;
    attachments?: Array<{
      filename: string;
      content: string | Buffer;
      contentType?: string;
    }>;
  }