Email sending code is not work after hosting

Question

1.00/5 (1 vote)

See more:

C#

MailMessage mm = new MailMessage("xyz@gmail.com", TextBoxEmail.Text.Trim());
                                        mm.Subject = "Password Recovery";
                                        mm.Body = string.Format("Hi ,<br /><br />Your password is .<br /><br />Thank You.");
                                        mm.IsBodyHtml = true;
                                        SmtpClient smtp = new SmtpClient();
                                        smtp.Host = "smtp.gmail.com";
                                        smtp.EnableSsl = true;
                                        NetworkCredential NetworkCred = new NetworkCredential();
                                        NetworkCred.UserName = "xyz@gmail.com";
                                        NetworkCred.Password = "xyz";
                                        smtp.UseDefaultCredentials = true;
                                        smtp.Credentials = NetworkCred;
                                        smtp.Port = 587;
                                        smtp.Send(mm);
                                        message = "Registration successful. Activation email has been sent.";
                                        ClientScript.RegisterStartupScript(GetType(), "alert", "alert('" + message + "');", true);

this is my code to send email after registration is successful. it work fine on my localhost iis server. but after deploying web-site on server email is not send to user. there is

C#

Object reference not set to an instance of an object.

error message shown. please help.

C#

same code work on password recovery page. but here it is not working.

I did some changes in code and also create a new page for registration now it is showing a following error

Object reference not set to an instance of an object.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

first i thought that it is error of mail sending code but it work fine on iis local server and also on other page. so i think may be it is a problem of button click event. just able to reach here. please some help me as i know i get my answer here.

my new code:

C#

using (MailMessage mail = new MailMessage())
                {
                    mail.From = new MailAddress("xyz@gmail.com");
                    mail.Subject = "mailSubject";
                    mail.Body = "mailBody";
                    mail.IsBodyHtml = true;

                    mail.To.Add("xyz@gmail.com");



                    using (SmtpClient smtp = new SmtpClient("smtp.gmail.com", 587))//2nd parameter is PORT No.
                    {
                        smtp.Credentials = new System.Net.NetworkCredential("xyz@gmail.com", "xyz");
                        smtp.EnableSsl = true;//set this as your Host Name properties, for gmail,its true
                        smtp.Send(mail);//actual sending operation here
                    }
                }

What I have tried:

C#

MailMessage mm = new MailMessage("xyz@gmail.com", TextBoxEmail.Text.Trim());
                                        mm.Subject = "Password Recovery";
                                        mm.Body = string.Format("Hi ,<br /><br />Your password is .<br /><br />Thank You.");
                                        mm.IsBodyHtml = true;
                                        SmtpClient smtp = new SmtpClient();
                                        smtp.Host = "smtp.gmail.com";
                                        smtp.EnableSsl = true;
                                        NetworkCredential NetworkCred = new NetworkCredential();
                                        NetworkCred.UserName = "xyz@gmail.com";
                                        NetworkCred.Password = "xyz";
                                        smtp.UseDefaultCredentials = true;
                                        smtp.Credentials = NetworkCred;
                                        smtp.Port = 587;
                                        smtp.Send(mm);
                                        message = "Registration successful. Activation email has been sent.";
                                        ClientScript.RegisterStartupScript(GetType(), "alert", "alert('" + message + "');", true);

this is my code to send email after registration is successful. it work fine on my localhost iis server. but after deploying web-site on server email is not send to user. please help.

Posted 29-May-16 23:02pm

Kishor-KW

Updated 31-May-16 23:26pm

v7

Add a Solution

Comments

F-ES Sitecore 30-May-16 6:09am

You have usedefaultcredentials set to true, it should be false.

http://forums.asp.net/post/5825785.aspx

Kishor-KW 30-May-16 9:09am

same code work on password recovery page. but here it is not working.

F-ES Sitecore 31-May-16 5:30am

This is one of the most frequently asked questions, google for sending email through gmail. The fact that it works in one scenario but not another means your code is not at fault, there are lots of reasons gmail won't send your mail, many are extensively documented. The only real solution is to not use gmail to send mail in the first place.

Kishor-KW 31-May-16 5:39am

then what to use? yahoo?

F-ES Sitecore 31-May-16 6:12am

No, use the smtp server provided by your webhost.

Kishor-KW 31-May-16 6:15am

means,

smtp.Host=smtp.mydomainname.com

right?

F-ES Sitecore 31-May-16 6:21am

It will be something like that, consult the documentation that comes with your hosting, or look at the control panel for it, or ask them which server to use.

Kishor-KW 31-May-16 6:22am

ok

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2016-05-29T23:29:00

Solution 1

Probably, it's your NetworkCred values: I know you have substituted values into the code, but I suspect that gmail is rejecting your credentials. Try changing:

C#

smtp.UseDefaultCredentials = true;

To:

C#

smtp.UseDefaultCredentials = false;

And double check the username and password you are sending to gmail.

Posted 29-May-16 23:29pm

OriginalGriff

Comments

Kishor-KW 30-May-16 5:37am

i did that changes but still it is not working. username and password are right.

Kishor-KW 30-May-16 9:09am

same code work on password recovery page. but here it is not working.

Luc Pattyn 6-Jun-16 20:22pm

Hi Griff,

My C# desktop applications just started having trouble sending emails using gmail; seems Google has enabled OAuth 2.0 now, and a simple credential isn't sufficient any more.

I'm eager to read a nice article on how to do OAuth 2.0, still googling though... Any suggestions? Or spare time?

BTW: of course one can change the gmail account to "Allow less secure apps" but that doesn't sound like the right way as it most likely disables OAuth 2.0 all together.

Cheers,

Luc

OriginalGriff 7-Jun-16 6:50am

Hi Luc!
Long time no speak - how you doing? Good to see you back here.
I haven't had to deal with OAuth 2.0 yet - but it's on my (copious) TODO so I'm up to speed when I do need it. Guess I'll have to move it up the list... :sigh:

Prateek Dalbehera · Answer 2 · 2016-05-30T01:15:00

Solution 2

Hi Member__979,

You can try the below code and again if it doesnt work , then please upload the exact error message sothat we will be narrow down the issue properly. It also may due to some network related issue which is not allowing to send.

C#

using (MailMessage mail = new MailMessage())
                {
                    mail.From = new MailAddress("sendersMailAddressHere");
                    mail.Subject = mailSubject;
                    mail.Body = mailBody;
                    mail.IsBodyHtml = true;

                    mail.To.Add("Toaddress");
                    mail.CC.Add("CCaddress");
                        

                    using (SmtpClient smtp = new SmtpClient("hostNameHere",587))//2nd parameter is PORT No.
                    {
			smtp.Credentials = new System.Net.NetworkCredential("sendersEmail", "sendersPassword");//supply userId & psd here
       			smtp.EnableSsl = true;//set this as your Host Name properties, for gmail,its true
                        smtp.Send(mail);//actual sending operation here
                    }
                }

Thanks,
Prateek

Posted 30-May-16 1:15am

Prateek Dalbehera

Updated 30-May-16 19:40pm

v3

Comments

Kishor-KW 30-May-16 7:46am

what is smtpTos,smtpCCs? as i tried but not work.

Prateek Dalbehera 31-May-16 1:38am

sorry,these are variables of my code, you can simply write, mail.To.Add() and mail.CC.Add(). Please post the error message what u are getting, then only somebody can identify what the actual issue is.

Kishor-KW 31-May-16 1:42am

there is no error.thats why it is tough to understand, just mail is not send.
but same code is work on other page. how it is possible?

Prateek Dalbehera 31-May-16 2:31am

Its quite complicated then if there will be network issues then u ll not be able to send any mail. There is an event for mail sending completed in C#, try if this event is hit or not after sending mail.

//
// Summary:
// Raises the System.Net.Mail.SmtpClient.SendCompleted event.
//
// Parameters:
// e:
// An System.ComponentModel.AsyncCompletedEventArgs that contains event data.
protected void OnSendCompleted(AsyncCompletedEventArgs e);

Prateek Dalbehera 31-May-16 2:34am

Also, try to write this just before smtp.send method, below is not the advised way but you try just for testing purpose.

ServicePointManager.ServerCertificateValidationCallback =
delegate(object s, X509Certificate certificate,
X509Chain chain, SslPolicyErrors sslPolicyErrors)
{ return true; };

Kishor-KW 31-May-16 2:53am

what it will do?

Prateek Dalbehera 31-May-16 2:58am

If ur mail sending is failed due to any certificate issues, then it will fix that but as i said not advisable to use, have u tried the event what i mentioned above.

Kishor-KW 31-May-16 4:17am

it gives a syntax error...like token is invalid ...and error red line below
X509Certificate certificate,X509Chain chain, SslPolicyErrors slPolicyErrors

Prateek Dalbehera 31-May-16 5:12am

Have u included the required namespaces for that???

Kishor-KW 31-May-16 5:39am

which one?

Kishor-KW 31-May-16 16:42pm

hey...I tried to ,make changes into the code ...now I am getting following error.

Object reference not set to an instance of an object.

now can you help me. I know why this error occured but there is no space for this error. may be issue in code of mail. please help

Prateek Dalbehera 1-Jun-16 5:50am

Please debug and mention exactly at which point you are getting null reference issue.

Kishor-KW 1-Jun-16 5:53am

actually on my visual studio it do not give error, but after hosting it, it give a error. i don't know how to debug it after hosting

Prateek Dalbehera 2-Jun-16 1:17am

Its clearly a network related issue if ur code is working in ur local machine... plz consult a senior developer regarding it.

Kishor-KW 30-May-16 9:07am

same code work on password recovery page. but here it is not working.