如何在 ASP.NET C # 中发送电子邮件

小开

You can try this using hotmail like this:-

MailMessage o = new MailMessage("From", "To","Subject", "Body");
NetworkCredential netCred= new NetworkCredential("Sender Email","Sender Password");
SmtpClient smtpobj= new SmtpClient("smtp.live.com", 587);
smtpobj.EnableSsl = true;
smtpobj.Credentials = netCred;
smtpobj.Send(o);

小开

最佳答案

Just go through the below code.

SmtpClient smtpClient = new SmtpClient("mail.MyWebsiteDomainName.com", 25);


smtpClient.Credentials = new System.Net.NetworkCredential("info@MyWebsiteDomainName.com", "myIDPassword");
// smtpClient.UseDefaultCredentials = true; // uncomment if you don't want to use the network credentials
smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
smtpClient.EnableSsl = true;
MailMessage mail = new MailMessage();


//Setting From , To and CC
mail.From = new MailAddress("info@MyWebsiteDomainName", "MyWeb Site");
mail.To.Add(new MailAddress("info@MyWebsiteDomainName"));
mail.CC.Add(new MailAddress("MyEmailID@gmail.com"));


smtpClient.Send(mail);

小开

Try using this code instead. Note: In the "from address" give your correct email id and password.

protected void btn_send_Click(object sender, EventArgs e)
{


System.Net.Mail.MailMessage mail = new System.Net.Mail.MailMessage();
mail.To.Add("to gmail address");
mail.From = new MailAddress("from gmail address", "Email head", System.Text.Encoding.UTF8);
mail.Subject = "This mail is send from asp.net application";
mail.SubjectEncoding = System.Text.Encoding.UTF8;
mail.Body = "This is Email Body Text";
mail.BodyEncoding = System.Text.Encoding.UTF8;
mail.IsBodyHtml = true;
mail.Priority = MailPriority.High;
SmtpClient client = new SmtpClient();
client.Credentials = new System.Net.NetworkCredential("from gmail address", "your gmail account password");
client.Port = 587;
client.Host = "smtp.gmail.com";
client.EnableSsl = true;
try
{
client.Send(mail);
Page.RegisterStartupScript("UserMsg", "<script>alert('Successfully Send...');if(alert){ window.location='SendMail.aspx';}</script>");
}
catch (Exception ex)
{
Exception ex2 = ex;
string errorMessage = string.Empty;
while (ex2 != null)
{
errorMessage += ex2.ToString();
ex2 = ex2.InnerException;
}
Page.RegisterStartupScript("UserMsg", "<script>alert('Sending Failed...');if(alert){ window.location='SendMail.aspx';}</script>");
}
}

小开

Try the following :

try
{
var fromEmailAddress =  ConfigurationManager.AppSettings["FromEmailAddress"].ToString();
var fromEmailDisplayName = ConfigurationManager.AppSettings["FromEmailDisplayName"].ToString();
var fromEmailPassword = ConfigurationManager.AppSettings["FromEmailPassword"].ToString();
var smtpHost = ConfigurationManager.AppSettings["SMTPHost"].ToString();
var smtpPort = ConfigurationManager.AppSettings["SMTPPort"].ToString();


string body = "Your registration has been done successfully. Thank you.";
MailMessage message = new MailMessage(new MailAddress(fromEmailAddress, fromEmailDisplayName), new MailAddress(ud.LoginId, ud.FullName));
message.Subject = "Thank You For Your Registration";
message.IsBodyHtml = true;
message.Body = body;


var client = new SmtpClient();
client.Credentials = new NetworkCredential(fromEmailAddress, fromEmailPassword);
client.Host = smtpHost;
client.EnableSsl = true;
client.Port = !string.IsNullOrEmpty(smtpPort) ? Convert.ToInt32(smtpPort) : 0;
client.Send(message);
}
catch (Exception ex)
{
throw (new Exception("Mail send failed to loginId " + ud.LoginId + ", though registration done."));
}

And then in you web.config add the following in between

<!--Email Config-->
<add key="FromEmailAddress" value="sender emailaddress"/>
<add key="FromEmailDisplayName" value="Display Name"/>
<add key="FromEmailPassword" value="sender Password"/>
<add key="SMTPHost" value="smtp-proxy.tm.net.my"/>
<add key="SMTPPort" value="smptp Port"/>

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Check this out .... it works

http://www.aspnettutorials.com/tutorials/email/email-aspnet2-csharp/

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Net.Mail;


public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{


}


protected void btnSubmit_Click(object sender, EventArgs e)
{
try
{
MailMessage message = new MailMessage(txtFrom.Text, txtTo.Text, txtSubject.Text, txtBody.Text);
SmtpClient emailClient = new SmtpClient(txtSMTPServer.Text);
emailClient.Send(message);
litStatus.Text = "Message Sent";
}
catch (Exception ex)
{
litStatus.Text=ex.ToString();
}
}
}

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MailMessage mm = new MailMessage(txtEmail.Text, txtTo.Text);
mm.Subject = txtSubject.Text;
mm.Body = txtBody.Text;
if (fuAttachment.HasFile)//file upload select or not
{
string FileName = Path.GetFileName(fuAttachment.PostedFile.FileName);
mm.Attachments.Add(new Attachment(fuAttachment.PostedFile.InputStream, FileName));
}
mm.IsBodyHtml = false;
SmtpClient smtp = new SmtpClient();
smtp.Host = "smtp.gmail.com";
smtp.EnableSsl = true;
NetworkCredential NetworkCred = new NetworkCredential(txtEmail.Text, txtPassword.Text);
smtp.UseDefaultCredentials = true;
smtp.Credentials = NetworkCred;
smtp.Port = 587;
smtp.Send(mm);
Response.write("Send Mail");

View Video: https://www.youtube.com/watch?v=bUUNv-19QAI

小开

If you want to generate your email bodies in razor, you can use Mailzory. Also, you can download the nuget package from here.

// template path
var viewPath = Path.Combine("Views/Emails", "hello.cshtml");
// read the content of template and pass it to the Email constructor
var template = File.ReadAllText(viewPath);


var email = new Email(template);


// set ViewBag properties
email.ViewBag.Name = "Johnny";
email.ViewBag.Content = "Mailzory Is Funny";


// send email
var task = email.SendAsync("mailzory@outlook.com", "subject");
task.Wait()

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This is the easiest script to test.

<%@ Import Namespace="System.Net" %>
<%@ Import Namespace="System.Net.Mail" %>


<script language="C#" runat="server">
protected void Page_Load(object sender, EventArgs e)
{
//create the mail message
MailMessage mail = new MailMessage();


//set the addresses
mail.From = new MailAddress("From email account");
mail.To.Add("To email account");


//set the content
mail.Subject = "This is a test email from C# script";
mail.Body = "This is a test email from C# script";
//send the message
SmtpClient smtp = new SmtpClient("mail.domainname.com");


NetworkCredential Credentials = new NetworkCredential("to email account", "Password");
smtp.Credentials = Credentials;
smtp.Send(mail);
lblMessage.Text = "Mail Sent";
}
</script>
<html>
<body>
<form runat="server">
<asp:Label id="lblMessage" runat="server"></asp:Label>
</form>
</body>

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You can try MailKit MailKit is an Open Source cross-platform .NET mail-client library that is based on MimeKit and optimized for mobile devices. You can use easily in your application.You can download from here.

                MimeMessage mailMessage = new MimeMessage();
mailMessage.From.Add(new MailboxAddress(fromName, from@address.com));
mailMessage.Sender = new MailboxAddress(senderName, sender@address.com);
mailMessage.To.Add(new MailboxAddress(emailid, emailid));
mailMessage.Subject = subject;
mailMessage.ReplyTo.Add(new MailboxAddress(replyToAddress));
mailMessage.Subject = subject;
var builder = new BodyBuilder();
builder.TextBody = "Hello There";
try
{
using (var smtpClient = new SmtpClient())
{
smtpClient.Connect("HostName", "Port", MailKit.Security.SecureSocketOptions.None);
smtpClient.Authenticate("user@name.com", "password");


smtpClient.Send(mailMessage);
Console.WriteLine("Success");
}
}
catch (SmtpCommandException ex)
{
Console.WriteLine(ex.ToString());
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}

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According to this :

SmtpClient and its network of types are poorly designed, we strongly recommend you use https://github.com/jstedfast/MailKit and https://github.com/jstedfast/MimeKit instead.

Reference : https://learn.microsoft.com/en-us/dotnet/api/system.net.mail.smtpclient?view=netframework-4.8

It's better to use MailKit to send emails :

var message = new MimeMessage ();
message.From.Add (new MailboxAddress ("Joey Tribbiani", "joey@friends.com"));
message.To.Add (new MailboxAddress ("Mrs. Chanandler Bong", "chandler@friends.com"));
message.Subject = "How you doin'?";


message.Body = new TextPart ("plain") {
Text = @"Hey Chandler,
I just wanted to let you know that Monica and I were going to go play some paintball, you in?
-- Joey"
};


using (var client = new SmtpClient ()) {
// For demo-purposes, accept all SSL certificates (in case the server supports STARTTLS)
client.ServerCertificateValidationCallback = (s,c,h,e) => true;


client.Connect ("smtp.friends.com", 587, false);


// Note: only needed if the SMTP server requires authentication
client.Authenticate ("joey", "password");


client.Send (message);
client.Disconnect (true);
}

小开

Just pass parameter like body - The content(query) from the customer
subject - subject that defined in mail subject
username - nothing name anything
mail - mail (required)

   public static bool SendMail(String body, String subject, string username, String mail)
{
bool isSendSuccess = false;
try
{
var fromEmailAddress = ConfigurationManager.AppSettings["FromEmailAddress"].ToString();
var fromEmailDisplayName = ConfigurationManager.AppSettings["FromEmailDisplayName"].ToString();
var fromEmailPassword = ConfigurationManager.AppSettings["FromEmailPassword"].ToString();
var smtpHost = ConfigurationManager.AppSettings["SMTPHost"].ToString();
var smtpPort = ConfigurationManager.AppSettings["SMTPPort"].ToString();




MailMessage message = new MailMessage(new MailAddress(fromEmailAddress, fromEmailDisplayName),
new MailAddress(mail, username));
message.Subject = subject;
message.IsBodyHtml = true;
message.Body = body;


var client = new SmtpClient();
client.UseDefaultCredentials = false;
client.Credentials = new NetworkCredential(fromEmailAddress, fromEmailPassword);
client.Host = smtpHost;
client.EnableSsl = false;
client.Port = !string.IsNullOrEmpty(smtpPort) ? Convert.ToInt32(smtpPort) : 0;
client.Send(message);
isSendSuccess = true;
}
catch (Exception ex)
{
throw (new Exception("Mail send failed to loginId " + mail + ", though registration done."+ex.ToString()+"\n"+ex.StackTrace));
}


return isSendSuccess;
}

if your using go daddy server this work . add this in web.config

  <appSettings>
---other ---setting


<add key="FromEmailAddress" value="myemail@gmail.com" />
<add key="FromEmailDisplayName" value="anyname" />
<add key="FromEmailPassword" value="mypassword@" />
<add key="SMTPHost" value="relay-hosting.secureserver.net" />
<add key="SMTPPort" value="25" />


</appSettings>

if you are using localhost or vps server change this configuration to this

 <appSettings>
---other ---setting


<add key="FromEmailAddress" value="myemail@gmail.com" />
<add key="FromEmailDisplayName" value="anyname" />
<add key="FromEmailPassword" value="mypassword@" />
<add key="SMTPHost" value="smtp.gmail.com" />
<add key="SMTPPort" value="587" />
</appSettings>

change the code

          client.EnableSsl = true;

if your are using gmail please enable secure app. using this link https://myaccount.google.com/lesssecureapps?pli=1&rapt=AEjHL4Pd6h3XxE663Flvd-FfeRXxW_eNrIsGTBlZklgkAHZEeuHvheCQuZ1-djB9uIWaB-2EV7hyLCU0dWKA7D0JzYKe4ZRkuA

小开

    using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Globalization;
using System.Text.RegularExpressions;
    

/// <summary>
/// Summary description for RegexUtilities
/// </summary>
public class RegexUtilities
{
bool InValid = false;
    

public bool IsValidEmail(string strIn)
{
InValid = false;
if (String.IsNullOrEmpty(strIn))
return false;
    

// Use IdnMapping class to convert Unicode domain names.
strIn = Regex.Replace(strIn, @"(@)(.+)$", this.DomainMapper);
if (InValid)
return false;
    

// Return true if strIn is in valid e-mail format.
return Regex.IsMatch(strIn, @"^(?("")(""[^""]+?""@)|(([0-9a-z]((\.(?!\.))|[-!#\$%&'\*\+/=\?\^`\{\}\|~\w])*)(?<=[0-9a-z])@))" + @"(?(\[)(\[(\d{1,3}\.){3}\d{1,3}\])|(([0-9a-z][-\w]*[0-9a-z]*\.)+[a-z0-9]{2,17}))$",
RegexOptions.IgnoreCase);
}
    

private string DomainMapper(Match match)
{
// IdnMapping class with default property values.
IdnMapping idn = new IdnMapping();
    

string domainName = match.Groups[2].Value;
try
{
domainName = idn.GetAscii(domainName);
}
catch (ArgumentException)
{
InValid = true;
}
return match.Groups[1].Value + domainName;
}
    

}






private void GetSendEmInfo()
{
#region For Get All Type Email Informations..!!
IPL.DoId = ddlName.SelectedValue;
DataTable dt = IdBL.GetEmailS(IPL);
if (dt.Rows.Count > 0)
{
hid_MailId.Value = dt.Rows[0]["MailId"].ToString();
hid_UsedPName.Value = dt.Rows[0]["UName"].ToString();
hid_EmailSubject.Value = dt.Rows[0]["EmailSubject"].ToString();
hid_EmailBody.Value = dt.Rows[0]["EmailBody"].ToString();
hid_EmailIdName.Value = dt.Rows[0]["EmailIdName"].ToString();
hid_EmPass.Value = dt.Rows[0]["EPass"].ToString();
hid_SeName.Value = dt.Rows[0]["SenName"].ToString();
hid_TNo.Value = dt.Rows[0]["TeNo"].ToString();
hid_EmaLimit.Value = dt.Rows[0]["EmailLimit"].ToString();
hidlink.Value = dt.Rows[0][link"].ToString();
}
#endregion


#region For Set Some Local Variables..!!
int StartLmt, FinalLmt, SendCurrentMail;
StartLmt = FinalLmt = SendCurrentMail = 0;
bool Valid_LimitMail;
Valid_LimitMail = true;
/**For Get Finalize Limit For Send Mail**/
FinalLmt = Convert.ToInt32(hid_EmailmaxLimit.Value);
#region For Check Email Valid Limits..!!
if (FinalLmt > 0)
{
Valid_LimitMail = true;
}
else
{
Valid_LimitMail = false;
}
#endregion
/**For Get Finalize Limit For Send Mail**/
#endregion


if (Valid_LimitMail == true)
{
#region For Send Current Email Status..!!
bool EmaiValid;
string CreateFileName;
string retmailflg = null;
EmaiValid = false;
#endregion


#region For Set Start Limit And FinalLimit Send No Of Email..!!
mPL.SendDate = DateTime.Now.ToString("dd-MMM-yyyy");
DataTable dtsendEmail = m1BL.GetEmailSendLog(mPL);
if (dtsendEmail.Rows.Count > 0)
{
StartLmt = Convert.ToInt32(dtsendEmail.Rows[0]["SendNo_Of_Email"].ToString());
}
else
{
StartLmt = 0;
}
#endregion


#region For Find Grid View Controls..!!
for (int i = 0; i < GrdEm.Rows.Count; i++)
{
#region For Find Grid view Controls..!!
CheckBox Chk_SelectOne = (CheckBox)GrdEmp.Rows[i].FindControl("chkSingle");
Label lbl_No = (Label)GrdEmAtt.Rows[i].FindControl("lblGrdCode");
lblCode.Value = lbl_InNo.Text;


Label lbl_EmailId = (Label)GrdEomAtt.Rows[i].FindControl("lblGrdEmpEmail");


#endregion


/**Region For If Check Box Checked Then**/
if (Chk_SelectOne.Checked == true)
{
if (!string.IsNullOrEmpty(lbl_EmailId.Text))
{
#region For When Check Box Checked..!!
/**If Start Limit Less Or Equal To Then Condition Performs**/
if (StartLmt < FinalLmt)
{
StartLmt = StartLmt + 1;
}
else
{
Valid_LimitMail = false;
EmaiValid = false;
}
/**End Region**/
string[] SplitClients_Email = lbl_EmailId.Text.Split(',');
string Send_Email, Hold_Email;
Send_Email = Hold_Email = "";


int CountEmail;/**Region For Count Total Email**/
CountEmail = 0;/**First Time Email Counts Zero**/


Hold_Email = SplitClients_Email[0].ToString().Trim().TrimEnd().TrimStart().ToString();
/**Region For If Clients Have One Email**/
#region For First Emails Send On Client..!!
if (SplitClients_Email[0].ToString() != "")
{
if (EmailRegex.IsValidEmail(Hold_Email))
{
Send_Email = Hold_Email;
CountEmail = 1;
EmaiValid = true;
}
else
{
EmaiValid = false;
}
}
#endregion
/**Region For If Clients Have One Email**/
/**Region For If Clients Have Two Email**/


/**Region For If Clients Have Two Email**/
if (EmaiValid == true)
{
#region For Create Email Body And Create File Name..!!
//fofile = Server.MapPath("PDFs");
fofile = Server.MapPath("~/vvv/vvvv/") + "/";
CreateFileName = lbl_INo.Text.ToString() + "_1" + ".Pdf";/**Create File Name**/
string[] orimail = Send_Email.Split(',');
string Billbody, TempInvoiceId;
// DateTime dtLstdate = new DateTime(Convert.ToInt32(txtYear.Text), Convert.ToInt32(ddlMonth.SelectedValue), 16);


//  DateTime IndtLmt = dtLstdate.AddMonths(1);
TempInvoiceId = "";


//byte[] Buffer = Encrypt.Encryptiondata(lbl_InvoiceNo.Text.ToString());
//TempInvoiceId = Convert.ToBase64String(Buffer);




#region Create Encrypted Path




byte[] EncCode = Encrypt.Encryptiondata(lbl_INo.Text);
hidEncrypteCode.Value = Convert.ToBase64String(EncECode);
#endregion


                        



//#region Create Email Body !!
//body = hid_EmailBody.Value.Replace("@greeting", lbl_CoName.Text).Replace("@free", hid_ToNo.Value).Replace("@llnk", "<a style='font-family: Tahoma; font-size: 10pt; color: #800000; font-weight: bold' href='http://1ccccc/ccc/ccc/ccc.aspx?EC=" + hidEncryptedCode.Value+ "' > C cccccccc </a>");
                          



body = hid_EmailBody.Value.Replace("@greeting", "Hii").Replace("@No", hid_No.Value);/*For Mail*/
//#endregion






#region For Email Sender Informations..!!
for (int j = 0; j < CountEmail; j++)
{
//if (File.Exists(fofile + "\\" + CreateFileName))
//{
#region
lbl_EmailId.Text = orimail[j];
retmailflg = "";


/**Region For Send Email For Clients**/
//retmailflg = SendPreMail("Wp From " + lbl_CName.Text + "", body, lbl_EmailId.Text, lbl_IeNo.Text, hid_EmailIdName.Value, hid_EmailPassword.Value);
retmailflg = SendPreMail(hid_EmailSubject.Value, Body, lbl_EmailId.Text, lbl_No.Text, hid_EmailIdName.Value, hid_EmailPassword.Value);
/**End Region**/


/**Region For Create Send Email Log  When Email Send Successfully**/
if (retmailflg == "True")
{
SendCurrentMail = Convert.ToInt32(SendCurrentMail) + 1;
StartLmt = Convert.ToInt32(StartLmt) + 1;


if (SendCurrentMail > 0)
{
CreateEmailLog(lbl_InNo.Text, StartLmt, hid_EmailIdName.Value, lbl_EmailId.Text);
                                        

}
}
                                



/**End Region**/
#endregion
//}
}
#endregion
}
#endregion
}
}
/**End Region**/
}
#endregion


}
       

}
private void CreateEmailLog(string UniqueId, int StartLmt, string FromEmailId, string TotxtEmailId)
{
FPL.EmailId_From = FromEmailId;
FPL.To_EmailId = TotxtEmailId;
FPL.SendDate = DateTime.Now.ToString("dd-MMM-yyyy");
FPL.EmailUniqueId = UniqueId;
FPL.SendNo_Of_Email = StartLmt.ToString();
FPL.LoginUserId = Session["LoginUserId"].ToString();
int i = FBL.InsertEmaDoc(FPL);
}


public string SendPreMail(string emsub, string embody, string EmailId, string FileId, string EmailFromId, string Password)
{
string retval = "False";
try
{
string emailBody, emailSubject, emailToList, emailFrom,
accountPassword, smtpServer;
bool enableSSL;
int port;


emailBody = embody;
emailSubject = emsub;
emailToList = EmailId;
emailFrom = EmailFromId;
accountPassword = Password;
smtpServer = "smtp.gmail.com";
enableSSL = true;
port = 587;


string crefilename;
string fofile;
fofile = Server.MapPath("PDF");
crefilename = FileId + ".Pdf";


string[] att = { crefilename };


string retemail, insertqry;
retemail = "";


retemail = SendEmail(emailBody, emailSubject, emailFrom, emailToList, att, smtpServer, enableSSL, accountPassword, port);


if (retemail == "True")
{


retval = retemail;
}
}
catch
{
retval = "False";
}
finally
{


}
return retval;
}


public string SendEmail(string emailBody, string emailSubject, string emailFrom, string emailToList, string[] attachedFiles, string smtpIPAddress, bool enableSSL, string accountPassword, int port)
{
MailMessage mail = new MailMessage();
string retflg;
retflg = "False";
try
{
mail.From = new MailAddress(emailFrom);
if (emailToList.Contains(";"))
{
emailToList = emailToList.Replace(";", ",");
}
mail.To.Add(emailToList);


mail.Subject = emailSubject;
mail.IsBodyHtml = true;
mail.Body = emailBody;




SmtpClient smtp = new SmtpClient();
smtp.Host = "smtp.gmail.com";
smtp.EnableSsl = true;
NetworkCredential NetworkCred = new NetworkCredential(emailFrom, accountPassword);
smtp.UseDefaultCredentials = true;
smtp.Credentials = NetworkCred;
smtp.Port = 587;
smtp.Send(mail);
retflg = "True";


}
catch
{
retflg = "False";
}
finally
{
mail.Dispose();
}
return retflg;
}

小开

Google may block sign-in attempts from some apps or devices that do not use modern security standards. Since these apps and devices are easier to break into, blocking them helps keep your account safer.

Some examples of apps that do not support the latest security standards include:

The Mail app on your iPhone or iPad with iOS 6 or below
The Mail app on your Windows phone preceding the 8.1 release
Some Desktop mail clients like Microsoft Outlook and Mozilla Thunderbird

Therefore, you have to enable Less Secure Sign-In (or Less secure app access) in your google account.

After sign into a google account, go to:

https://www.google.com/settings/security/lesssecureapps or https://myaccount.google.com/lesssecureapps

In C#, you can use the following code:

        MimeMessage message = new MimeMessage();
BodyBuilder Attachmint = new BodyBuilder();
message.From.Add(new MailboxAddress("name sender", "Mail From"));
message.To.Add(MailboxAddress.Parse("Mail To"));
message.Subject = Subject;
message.Body = new TextPart("plain")
{
Text = tex_body.Text + Massage
};


Attachmint.Attachments.Add("Attatchment Path");
message.Body = Attachmint.ToMessageBody();


SmtpClient client = new SmtpClient();
client.Connect("smtp.gmail.com", 465, true);
client.Authenticate("Mail from", "Password mail");
client.Send(message);

you can send mail from Gmail to Private Mail As X@PrivetCompany.com

小开

Answer Update 2023

C# code for Email (GMAIL) Service

using System;
using System.Net;
using System.Net.Mail;


namespace EmailApp
{
internal class Program
{
public static void Main(string[] args)
{
String SendMailFrom = "Sender Email";
String SendMailTo = "Reciever Email";
String SendMailSubject = "Email Subject";
String SendMailBody = "Email Body";


try
{
SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com",587);
SmtpServer.DeliveryMethod = SmtpDeliveryMethod.Network;
MailMessage email = new MailMessage();
// START
email.From = new MailAddress(SendMailFrom);
email.To.Add(SendMailTo);
email.CC.Add(SendMailFrom);
email.Subject = SendMailSubject;
email.Body = SendMailBody;
//END
SmtpServer.Timeout = 5000;
SmtpServer.EnableSsl = true;
SmtpServer.UseDefaultCredentials = false;
SmtpServer.Credentials = new NetworkCredential(SendMailFrom, "Google App Password");
SmtpServer.Send(email);


Console.WriteLine("Email Successfully Sent");
Console.ReadKey();
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
Console.ReadKey();
}


}
}
}

For further help, you can refer to: https://www.techaeblogs.live/2022/06/how-to-send-email-using-gmail.html