How to send email using ASP.NET?

Question

4.00/5 (1 vote)

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Hi guys!

I got an error in this part saying, "The SMTP server requires a secure connection or the client was not authenticated. " the browser is pointing at

smtp.Send(fromAddress, toAddress, subject, body);

. It is where the error. But I think it is not.

Here is my code:

protected void ImageButton3_Click(object sender, ImageClickEventArgs e)
    {
            
            GeneratePass(); //Generate System ID
            s = WebConfigurationManager.ConnectionStrings["amicassa"].ConnectionString;
            amicasaCon = new SqlConnection(s);
            amicasaCon.Open();

            SqlCommand cadd = new SqlCommand("Update users set system_id ='"+oldpassword.Text+"' WHERE username = '"+username.Text+"' ", amicasaCon);
            SqlDataReader rcd = cadd.ExecuteReader();
            rcd.Close();
            amicasaCon.Close();
            try
            {
                //here on button click what will done 
            SendMail();
            newpassword.Text = "";
            oldpassword.Text = "";
            Response.Redirect("ChangePassword.aspx");
            
        }
        catch (Exception) { }

       
    }

    protected void SendMail()
    {
        // Gmail Address from where you send the mail
        var fromAddress = "xxxxx@gmail.com";
        // any address where the email will be sending
        var toAddress = newpassword.Text.ToString();
        //Password of your gmail address
        const string fromPassword = "xxxxxxxx";
        // Passing the values and make a email formate to display
        string subject = oldpassword.Text.ToString();
        string body = "From: ADMIN "+"\n";
        body += "Email: " + newpassword.Text + "\n";
        body += "System ID : " + oldpassword.Text + "\n";
        body += "Please DO NOT REPLY" + "\n";
        // smtp settings
        var smtp = new System.Net.Mail.SmtpClient();
        {
            smtp.Host = "smtp.gmail.com";
            smtp.Port = 587;
            smtp.EnableSsl = true;
            smtp.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
            smtp.Credentials = new NetworkCredential(fromAddress, fromPassword);
            smtp.Timeout = 20000;
        }
        // Passing values to smtp object
        smtp.Send(fromAddress, toAddress, subject, body);
    }

Posted 27-Aug-14 16:38pm

DarkDreamer08

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5 solutions

Solution 4

please go through below link

Send Mail / Contact Form using ASP.NET and C#[^]

http://asp.net-tutorials.com/misc/sending-mails/[^]

Posted 27-Aug-14 18:13pm

Yogesh Kumar Tyagi

Solution 1

Check the link below
http://stackoverflow.com/questions/20906077/gmail-error-the-smtp-server-requires-a-secure-connection-or-the-client-was-not[^]

Hope this helps

Posted 27-Aug-14 16:55pm

ChauhanAjay

Comments

DarkDreamer08 27-Aug-14 23:02pm

I have read that and followed to. same error displays. That is why I switched back to my original code that I posted above. To be honest, yesterday, it works fine. but today, when I add some codes specifically the query, it does not work :(

Solution 3

C#

public static Boolean SendingMail(string From, string To, string Subject, string Body)
    {
        
            try
            {
                MailMessage m = new MailMessage("Uma<test@gmail.com>", To);
                m.Subject = Subject;
                m.Body = Body;
                m.IsBodyHtml = true;
                m.From = new MailAddress(From);
 
                m.To.Add(new MailAddress(To));
                SmtpClient smtp = new SmtpClient();
                smtp.Host = "smtp.gmail.com";
              
                NetworkCredential authinfo = new NetworkCredential("test@gmail.com","password");
                smtp.UseDefaultCredentials = false;
                smtp.Credentials = authinfo;
                smtp.Send(m);
                return true;
 
               
 

            }
            catch (Exception ex)
            {
                return false;
            }
        }

Posted 27-Aug-14 17:53pm

Gihan Liyanage

Comments

Gihan Liyanage 15-Sep-14 6:23am

Did you got a solution from my support, I can see you have not accepted any answer.If you are ok with this answer plz accept it. Then any user having same problem can identified it has solved the problem..

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Sergey Alexandrovich Kryukov · Accepted Answer · 2014-08-27T17:37:00

Solution 2

Please see:
http://msdn.microsoft.com/en-us/library/system.net.mail.smtpclient.enablessl%28v=vs.110%29.aspx[^],
http://msdn.microsoft.com/en-us/library/system.net.mail.smtpclient.credentials%28v=vs.110%29.aspx[^].

—SA

Posted 27-Aug-14 17:37pm

Sergey Alexandrovich Kryukov

Comments

DarkDreamer08 28-Aug-14 1:25am

I fixed now the error. But I got a problem. It is just executing the query then it does not move to the next function which is to send mail after I press the image button. What should I do? :(

Sergey Alexandrovich Kryukov 28-Aug-14 1:40am

Not clear. What query, what "next function"? Isn't it a different question?
Did I answer your present question? Will you formally accept it?
—SA

DarkDreamer08 28-Aug-14 1:43am

it is about the above code. The query inside the Image button Event Handler. the next function I am pertaining is the SendMail() which is inside the try {}and catch{}

Sergey Alexandrovich Kryukov 28-Aug-14 1:47am

To start with, don't block propagation of exceptions with "catch (...) {}". You try-catch too locally. Remove try-catch at all from the handler. You should try up the stack, in this case, it could be the main event loop.
—SA

DarkDreamer08 28-Aug-14 1:55am

I just remove the try-catch. But the code inside the try-catch remains because I am calling it after the query executes fine. Now, an error displayed, "The operation has timed out.Error in smtp.Send(fromAddress, toAddress, subject, body);"

Sergey Alexandrovich Kryukov 28-Aug-14 2:00am

All right for now. Now you can see the exception. Now, is SMTP server properly set up? In particular, have you been able to send a message using the same authentication with some existing client program?
—SA

DarkDreamer08 1-Sep-14 21:10pm

PLease, Kindly help me out here : http://www.codeproject.com/Questions/813709/How-t-make-an-auto-complete-textbox-without-using :(

Raul Iloc · Accepted Answer · 2014-08-27T19:10:00

Solution 5

It seems that your current SMTP settings are not OK.
In your case for SSL Enabled the STMP port should be: 465

You could see details about sending email by using "gmail" settings problems and solutions at the next links:
https://support.google.com/mail/answer/78775?hl=en[^]

Posted 27-Aug-14 19:10pm

Raul Iloc

Comments

DarkDreamer08 28-Aug-14 1:24am

I fixed now the error. But it does not send any message to the email that I put. It just doing the first condition which is updating the system ID in the database then nothing happens next whenever I press the image button. What should I do?

Raul Iloc 28-Aug-14 1:29am

1.Please check if the email is not in the SPAN list, or maybe the email will come after a delay.
2.You should try first to test your code by sending email to another existing gmail account.

DarkDreamer08 28-Aug-14 1:33am

actually, it works fine yesterday when I followed the steps you gave to me on the post about sending email yesterday. So, today, I just add a query to update first the system ID generated by the system to the database before it send to the user's email. When I run the program, it does not send, but it executes the query fine.

Raul Iloc 28-Aug-14 1:47am

Then, if you have the code from yesterday before your new changes, the sending email part should work also today, because accessing the database is not related with the sending email, but check if the data read from there is valid, maybe is a wrong value for email address read from the database or something. So you should inspect your code by using Debug during execution.

DarkDreamer08 28-Aug-14 1:50am

The code above is the code you taught to me yesterday. Exactly as it is. I just included there the codes for database.

DarkDreamer08 28-Aug-14 1:27am

Where I could find "allow authentication" for SMTP? Maybe it will be the thing to solved my problem.

Raul Iloc 28-Aug-14 1:33am

1.You should check in your email client, like Outlook, in the account settings -> Server Settings.
2.But you could try to send emails without SSL enabled.

DarkDreamer08 28-Aug-14 1:34am

I am using my gmail account. Where I could find it?

Raul Iloc 28-Aug-14 1:43am

You should check your gamil Settings (there is an icon button in the upper right corner).

DarkDreamer08 28-Aug-14 1:47am

I found the settings of my gmail account with the gear icon. But I do not know what I will I am going to click next. I am sorry :( I am just new in ASP.Net. It is just last July that I created my account here about ASP.Net :(

Raul Iloc 28-Aug-14 3:55am

I just checked by using my gmail account, so you have to do the next settings:
1.Enable IMAP access;
2.Use "https://www.google.com/settings/security/lesssecureapps" to "allow the application less secured".
3.Use 587 as SMTP port number with SSL enabled and smtp.UseDefaultCredentials = false;

DarkDreamer08 28-Aug-14 4:19am

still there is an error saying,"THe SMTP requires a secure connection or the client was not authenticated." How to fix that error?

Raul Iloc 28-Aug-14 4:22am

You should set:
smtp.Port = 587; smtp.EnableSsl = true; smtp.UseDefaultCredentials = false;

DarkDreamer08 28-Aug-14 4:37am

Hey friend! it's working now!!! THANK YOU SO MUCH!!!

Raul Iloc 28-Aug-14 4:38am

Welcome!

DarkDreamer08 1-Sep-14 21:10pm

Please HELP me out here :( http://www.codeproject.com/Questions/813709/How-t-make-an-auto-complete-textbox-without-using