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I am sending mails using my live account and my code works fine on localhost but gives an exception on server:
Mailbox unavailable. The server response was: 5.7.3
Requested action aborted; user not authenticated
Below is my code:
public static string SendEmail(string receivermailid, string subject, string body)
        MailMessage MyMailMessage = new MailMessage("", receivermailid, subject, body);
        MyMailMessage.IsBodyHtml = true;
        NetworkCredential mailAuthentication = new
        NetworkCredential("", "xxxx");
        SmtpClient mailclient = new SmtpClient("", 25);
        mailclient.EnableSsl = true;
        mailclient.UseDefaultCredentials = false;
        mailclient.Credentials = mailAuthentication;

            return "Sent successfully";
        catch (SmtpException ex)
            return ex.Message;
Updated 5-Jul-13 5:18am
Richard MacCutchan 5-Jul-13 10:56am
"doesn't work" is not a very good description of the error. Try adding some useful detail about exactly what happens and what error codes or messages you get.
lucky050 5-Jul-13 11:17am
Thanks for the prompt response. It gives an exception:
Mailbox unavailable. The server response was: 5.7.3
Requested action aborted; user not authenticated
Richard MacCutchan 5-Jul-13 11:22am
"user not authenticated" suggests that it requires different authentication settings.
lucky050 5-Jul-13 11:37am
I should be most grateful if you would send me the sample code..
[no name] 5-Jul-13 11:45am
Try using port 587
lucky050 5-Jul-13 12:08pm
i changed my port to 587 still its not working but now my method is not returning any message
[no name] 5-Jul-13 12:40pm
Okay so your error message went away which was the basis for your question.... what does "still its not working" mean?
idenizeni 5-Jul-13 19:52pm
Are you 100% sure the credentials you are supplying are correct and the email account exists on the
lucky050 6-Jul-13 7:15am
yes i m 100% sure... i've changed the credentials to server's mail and its working now.. it could be a firewall issue

1 solution

My guess is either the default credentials or SSL, but it's hard for us to say; We don't have access to your server...

Could be firewall trouble as well!

Good luck!

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