在 Visual Studio 2005 中将旧代码从 System.Web.Mail 更新为 System.Net.Mail：发送电子邮件时出现问题

using System.Net.Mail;

SmtpClient smtpClient = new SmtpClient("smtp.example.com", 587);

smtpClient.Credentials = new NetworkCredential("username", "password");

MailMessage mailMessage = new MailMessage("from@example.com", "to@example.com", "Subject", "Body");

smtpClient.Send(mailMessage);

using System.Net.Mail;

public void SendEmail()
{
    SmtpClient smtpClient = new SmtpClient("smtp.example.com", 587);
    smtpClient.Credentials = new NetworkCredential("username", "password");
    MailMessage mailMessage = new MailMessage("from@example.com", "to@example.com", "Subject", "Body");
    smtpClient.Send(mailMessage);
}