Error When Sending Mail With Asp.net C#

Hello all,

I want to send a mail after my user fill a form but i keep getting the following error "The smtp server requires a secure connection or the client was not authenticated 5.5.1. Authentication required". bellow is my code :

int cnt;
try
{
mEmail = Session["mEmail"].ToString();
// string password = "abraham@2013";
MailMessage Msg = new MailMessage();
Msg.From = new MailAddress(mEmail.Trim());
Msg.To.Add("[email protected]"); // create a frame for HR department
Msg.Bcc.Add("[email protected]"); //blind copy me
StreamReader reader = new StreamReader(Server.MapPath("~/SendMail.html"));
string readFile = reader.ReadToEnd();
string StrContent = "";
StrContent = readFile;
//Here replace the name with [MyName]
StrContent = StrContent.Replace("[MyName]", lblname.Text);
string mSubject = "APPLICATION FOR ANNUAL LEAVE";
StrContent = StrContent.Replace("[subject]", mSubject);
StrContent = StrContent.Replace("[date1]", txtFromDate.Text.Trim());
StrContent = StrContent.Replace("[date2]", txtToDate.Text.Trim());
StrContent = StrContent.Replace("[ddays]",txtNODays.Text.Trim())+" days";
Msg.Subject = mSubject + " FROM " + lblname.Text;
Msg.Body = StrContent.ToString();
Msg.IsBodyHtml = true;
SmtpClient smtp = new SmtpClient();
smtp.Host = "smtp.gmail.com"; //"mail.dnextageweb.com"; //
smtp.Port = 587;
smtp.EnableSsl = true;
smtp.Timeout = 40000;
smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
smtp.UseDefaultCredentials = false;
smtp.Credentials = new NetworkCredential("[email protected]", "Delladv!973@");
smtp.Send(Msg);
webMessage.Show("Mail sent successful.....");
return cnt = 1;
}
catch (Exception ex)
{
webMessage.Show("Error : " + ex.Message.ToString());
return cnt = -1;
}

please i have tried all i know, i need your help, how to get smtp.gmail.com to work.

Thank you all

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Rafnas T P9y ago
try

changing Msg.From = new MailAddress(mEmail.Trim());
to
Msg.From = new MailAddress("[email protected]");
Msg.To.Add(mEmail.Trim());
-1
Nilesh Shah9y ago
First of all, make sure you are typing your email and password correctly.

If that is OK, and still you face issues, then there is possibility that Google security settings are blocking your code.

When you try to login from some App or code, google setting comes into picture.

Log in to your google account

Go to https://myaccount.google.com/security

And scroll down to "Connected apps & sites"

Make sure that "Allow less secure apps" is ON

Hope this helps!
+2
Amit Gupta9y ago
If you are sending mail from gmail, less secure settings must be enable in setting.

Enable it from the below link
https://myaccount.google.com/security

Hope it helps
+1
Francis Susaimichael9y ago
Seems like some authentication issue. Can you double check the credentials that you supplied?
0