简单的邮件发送窗体，托管c++版：

添加空间引用：using namespace System::Net::Mail;
 using namespace System::Net::NetworkInformation;
 using namespace System::Net;

添加textbox和按钮。

代码：

private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
    String ^sm;
     MailMessage ^aMessage=gcnew MailMessage();
     if (textBox1->Text=="")
     {
      MessageBox::Show("填写地址");

     }
     else if(textBox2->Text=="")
     {
                   MessageBox::Show("xiejiandizhi");

     }
     else
     {

      try{
       aMessage = gcnew MailMessage(textBox2->Text->Trim(),textBox1->Text->Trim());
      sm= this->textBox2->Text;
      int s=sm->IndexOf('@');
      int l=sm->IndexOf('.');
      String ^sep=sm->Substring(s+1,l-s-1);
       //组合SMTP服务器地址
      String ^site = "smtp." + sep + ".com";
       SmtpClient ^client = gcnew SmtpClient(site);
       client->UseDefaultCredentials = false;
       NetworkCredential ^myCredential=gcnew NetworkCredential(textBox2->Text->Trim(),textBox3->Text);
       client->Credentials = myCredential;
       client->DeliveryMethod = SmtpDeliveryMethod::Network;

       //邮件主题
       aMessage->Subject =textBox4->Text;
       //邮件内容
       aMessage->Body =textBox5->Text;
       //发送电子邮件
       client->Send(aMessage);
       MessageBox::Show("邮件发送成功!");
      }
      catch(Exception ^ex)
      {
       MessageBox::Show(ex->Message);
      }
     }

注释：textbox1为收件人地址，box2为写件人地址，box为写件人地址密码，box4为邮件主题，box5为邮件内容。