c#之如何使用 C# MailMessage 检查电子邮件是否已送达

我正在使用下面的代码发送电子邮件，它在大多数时间都工作正常，在测试期间我们发现有时它无法发送电子邮件。我如何更改此代码以检查电子邮件传递状态或字体是否有任何其他故障。

        public static void SendEmail(string to, string subject, string message, bool isHtml) 
        { 
            try 
            { 
            var mail = new MailMessage(); 
 
            // Set the to and from addresses. 
            // The from address must be your GMail account 
            mail.From = new MailAddress("noreplyXYZ@gmail.com"); 
            mail.To.Add(new MailAddress(to)); 
 
            // Define the message 
            mail.Subject = subject; 
            mail.IsBodyHtml = isHtml; 
            mail.Body = message; 
 
            // Create a new Smpt Client using Google's servers 
            var mailclient = new SmtpClient(); 
            mailclient.Host = "smtp.gmail.com";//ForGmail 
            mailclient.Port = 587; //ForGmail 
 
 
            // This is the critical part, you must enable SSL 
            mailclient.EnableSsl = true;//ForGmail 
            //mailclient.EnableSsl = false; 
            mailclient.UseDefaultCredentials = true; 
 
            // Specify your authentication details 
            mailclient.Credentials = new System.Net.NetworkCredential("noreplyXYZ@gmail.com", "xxxx123");//ForGmail 
            mailclient.Send(mail); 
            mailclient.Dispose(); 
    } 
                    catch (Exception ex) 
                    { 
    throw ex; 
                        } 
    } 

我知道 SMTP 负责发送电子邮件，无法查看发送状态，但这是检查电子邮件发送状态的一种方法

更新代码(正确吗)

public static void SendEmail(string to, string subject, string message, bool isHtml) 
{ 
    var mail = new MailMessage(); 
 
    // Set the to and from addresses. 
    // The from address must be your GMail account 
    mail.From = new MailAddress("noreplyXYZ@gmail.com"); 
    mail.To.Add(new MailAddress(to)); 
 
    // Define the message 
    mail.Subject = subject; 
    mail.IsBodyHtml = isHtml; 
    mail.Body = message; 
 
    // Create a new Smpt Client using Google's servers 
    var mailclient = new SmtpClient(); 
    mailclient.Host = "smtp.gmail.com";//ForGmail 
    mailclient.Port = 587; //ForGmail 
 
    mailclient.EnableSsl = true;//ForGmail 
    //mailclient.EnableSsl = false; 
    mailclient.UseDefaultCredentials = true; 
 
    // Specify your authentication details 
    mailclient.Credentials = new System.Net.NetworkCredential("noreplyXYZ@gmail.com", "xxxx123");//ForGmail 
    mailclient.Send(mail); 
    mailclient.Dispose(); 
    try 
    { 
        mailclient.Send(mail); 
        mailclient.Dispose(); 
    } 
    catch (SmtpFailedRecipientsException ex) 
    { 
        for (int i = 0; i < ex.InnerExceptions.Length; i++) 
        { 
            SmtpStatusCode status = ex.InnerExceptions[i].StatusCode; 
            if (status == SmtpStatusCode.MailboxBusy ||status == SmtpStatusCode.MailboxUnavailable) 
            { 
                // Console.WriteLine("Delivery failed - retrying in 5 seconds."); 
                System.Threading.Thread.Sleep(5000); 
                mailclient.Send(mail); 
            } 
            else 
            { 
                //  Console.WriteLine("Failed to deliver message to {0}", ex.InnerExceptions[i].FailedRecipient); 
                throw ex; 
            } 
        } 
    } 
    catch (Exception ex) 
    { 
        //  Console.WriteLine("Exception caught in RetryIfBusy(): {0}",ex.ToString()); 
        throw ex; 
    } 
    finally 
    { 
        mailclient.Dispose(); 
    } 
 
}