Develop Reference

Go Daddy email SMTP not sending email but no error

I've recently purchased the essentials email package from GoDaddy and I am trying to set up sending email from my website via SMTP. I have the following code set up.
var smtp = new SmtpClient
{
Host = "mycoolwebsite.com.mail.protection.outlook.com",
Port = 25,
DeliveryMethod = SmtpDeliveryMethod.Network,
UseDefaultCredentials = false,
Credentials = new NetworkCredential("info#mycoolwebsite.com", "supersecurepassword")
};
using (var message = new MailMessage("info#mycoolwebsite.com", "myemail#test.com")
{
IsBodyHtml = true,
Subject = subject,
Body = body
})
{
smtp.Send(message);
}
This gets to send and doesn't throw any exceptions, however the email is not sent. I am very confused at why this doesn't work.
Has anyone got any ideas?

This is going to require TLS which means using MailKit's SMTP. You can get it using the NuGet package manager in Visual Studio. Search for MailKit by Jeffrey Stedfast.
Documentation is here as well.
Once you have all the references in place, use the MailKit.Net.Smtp.SmtpClient class:
Set "smtp.office365.com" as your host
Use port 587.
You will need to add this line after creating your smtp instance because you have no OAuth token:
smtp.AuthenticationMechanisms.Remove("XOAUTH2");
That will do what you need.
Here's an example of what the whole thing should look like:
string FromPseudonym = "MySite Support";
string FromAddress = "admin#MySite.com";
var message = new MimeMessage();
message.From.Add(new MailboxAddress(FromPseudonym, FromAddress));
message.To.Add(new MailboxAddress("Recipient Pseudonym", "RecipientAddress#somewhere.com"));
message.Subject = "Testing Email";
var bodyBuilder = new BodyBuilder();
string MsgBody = "Message Body stuff goes here";
bodyBuilder.HtmlBody = MsgBody;
message.Body = bodyBuilder.ToMessageBody();
using (var client = new SmtpClient())
{
client.Connect("smtp.office365.com", 587);
client.AuthenticationMechanisms.Remove("XOAUTH2");
client.Authenticate(FromAddress, "Your super secret password goes here");
client.Send(message);
client.Disconnect(true);
}
You'll need the following namespaces to be included:
using MimeKit;
using MimeKit.Utils;
using MailKit.Net.Smtp;

I've been where you are before. If you are running the app from your dev environment, the emails will not be sent. GoDaddy SMTP is configured so that emails will only be sent when requested from within their environment.
If you push the code to their host and run it, it will work. The most painful thing about this is that everything appears to go smoothly, but the SMTP client just eats the request and leaves you wondering why no email is sent.

Not knowing anything about GoDaddy's API, the only thing I can suggest, is maybe verify that the port is correct. It might require transport layer security, in which case port 25 will be closed.
For example, I think the office365 SMTP server (smtp.office365.com) requires secure SMTP and uses port 587.

How to use explicit SSL with System.Net.Mail SMTP

I've seen a lot of examples of implicit SSL (for use with the deprecated System.Web.Mail), but I'm using System.Net.Mail and would like a code example for how to send SMTP emails via explicit SSL.
My current sendEmail code is below - note that if I set EnableSsl = true, server returns a 500 error and the email is never sent. I assume because this is implicit SSL, which System.Net.Mail does not support:
using System.Net.Mail;
...
public static void SendEmail(string emailbody)
{
MailMessage mailMessage = new MailMessage("myDomain#me.com", "yourDomain#me.com");
mailMessage.IsBodyHtml = true;
mailMessage.Body = emailbody;
mailMessage.Subject = "My email";
SmtpClient smtpClient = new SmtpClient("smtp.me.com", 25);
// if false, email sends. If true, email does not send, server returns 500 error
smtpClient.EnableSsl = false;
smtpClient.Send(mailMessage);
}

You can't.
https://support.microsoft.com/en-us/help/950260/you-cannot-use-system-net-mail-smtpclient-to-send-an-e-mail-message-wi
You can supposedly use cdo.sys, but it's really old and I don't believe it's supported anymore. I'm also not sure it's available or usable since it came with Windows 2000.
Your best bet would be to setup an actual mail server to handle talking to the outside world and talk to it with your unencrypted port 25 connection. If you have a small box to dedicate, Postfix is a free, very lightweight and very robust SMTP server that would work nicely.

Why can't I send e-mail from a C# app when I can send e-mail from a mail client just fine?

I have a task to troubleshoot why a C# app is failing to send automated e-mail messages. I carefully checked the source code, and could find absolutely nothing wrong.
Therefore, I tried to send e-mail from Thunderbird, the e-mail client I normally use. I specified the same SMTP relay, the same UID and password, and everything worked fine.
Trying to isolate the problem, I tried writing a very short C# console app to see what might be going wrong. I wrote the following:
using System.Net;
using System.Net.Mail;
namespace ConsoleApp3
{
class Program
{
static void Main(string[] args)
{
var client = new SmtpClient("my.server.with.ssl", 465);
client.EnableSsl = true;
client.Credentials = new NetworkCredential("uid", "pwd");
var message = new MailMessage("me#example.com", "myemail#mydomain", "Test Message Subject", "Test Message Body");
client.Send(message);
}
}
}
I entered the same credentials that I used in Thunderbird. When I run the above, I get the following error:
Unhandled Exception: System.Net.Mail.SmtpException: Failure sending mail. ---> System.IO.IOException: Unable to read data from the transport connection: net_io_connectionclosed.
How can it be that e-mail is sent just fine from Thunderbird, but the simple programming above fails to work when I try to send an e-mail from a basic C# app?
Edit I tried changing the port number to 587 as suggested in the Question that #stuartd linked to, and in that case, I get an error that says The operation timed out.
Edit I've tried using other e-mail servers and adjusting the settings, but nothing works so far. I've tried connecting to the same SMTP server that I use for my personal e-mail and it shows an error that the connection times out.
Edit I can't say why, but everything seems to be working now in spite of the fact that I didn't change any code. It seems as if something odd happened with my connection.

try using the default constructor and specify the host only.
Also some servers require that the client be authenticated before the server sends e-mail on its behalf. Try changing the value of UseDefaultCredentials
var mail = new MailMessage();
mail.From = new MailAddress("xxx#gmx.net");
mail.To.Add("yyy#gmail.com");
mail.IsBodyHtml = true;
mail.Subject = "subject";
mail.Body = "content";
var client = new SmtpClient();
client.UseDefaultCredentials = false;
client.Host = "mail.gmx.net";
client.EnableSsl = true;
client.Credentials = new NetworkCredential("user", "pass");
client.Send(mail);
if that doesn't help than tell us the server name if its the public one

Try using:
SmtpClient smtpClient = new SmtpClient("mail.mymailhost.com");
smtpClient.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;

Sending out an automated email

I have an service that needs to send out automated emails on failures. I feel like i have it set up but i keep on receiving the following error:
Service not available, closing transmission channel. The server response
was: 4.3.2 Service not available
I cant quite figure out where i went wrong, but here is my code:
public static void AutoEmail()
{
try
{
SmtpClient newClient = new SmtpClient();
newClient.Host = "host name";
newClient.Port = Port number;
newClient.Credentials = new System.Net.NetworkCredential(
"username", "password");
MailMessage mail = new MailMessage();
mail.To.Add(new MailAddress("something#email.com"));
mail.Body = "This is a test message.";
mail.Subject = "Test - " + DateTime.Now;
mail.From = new MailAddress("something2#email.com");
newClient.Send(mail);
}
catch (Exception ex)
{
Log.WriteException("Error in Email", ex);
}
}
Any help would be much appreciated. Thanks!

Are you sure SMTP server you are using permits applications to send emails? I had met with similar issue and root cause was Exchange server was rejecting the send request due to insufficient permissions. And I have the same steps in my code as in yours. Check for permissions.

Have you tried
newClient .UseDefaultCredentials = true;
Does it help ?
The SMTP server name only works on a computer within the network that contains that SMTP server.

You need to make sure SMTP server's host name and port number in your program is correct. All the other code in your program seem fine.
I experienced the same error before. At the end, I changed to the correct host name and port number and everything works.
For example, Outlook.com Or Hotmail email accounts
host="smtp-mail.outlook.com" port="25" enableSsl="true"
https://www.outlook-apps.com/outlook-com-pop-settings/

Email Sender App with Images on Local Machine

I have a small email application that lets a user build a message from checkboxes and then send the message as an email. I am trying to add an image to the email, i.e. a logo or signature. The application worked fine but as I was reseaching getting the images into the email, I found that I should be using System.Net.Mail instead of Interop. So I changed my email class to the code below. Now I'm not recieving the emails. I'm assumeing this is because the code is set-up for a server and I just want to run this on my local machine. This is just something I'm playing with to help me understand some concepts so real world use is not going to be a factor. I just want to be able to test my little program on my Outlook email account locally. My code is as follows...
using System;
using System.Net.Mail;
using System.Net.Mime;
namespace Email_Notifier
{
public class EmailSender:Notification
{
string emailRecipient = System.Configuration.ConfigurationManager.AppSettings ["emailRecipient"];
public void SendMail(string message)
{
try
{
string strMailContent = message;
string fromAddress = "MyApp#gmail.com";
string toAddress = emailRecipient;
string contentId = "image1";
string path = (#"C:Libraries/Pictures/Logo.gif");
MailMessage mailMessage = new MailMessage(fromAddress, toAddress);
mailMessage.Subject = "Email Notification";
LinkedResource logo = new LinkedResource( path , MediaTypeNames.Image.Gif);
logo.ContentId = "Logo";
// HTML formatting for logo
AlternateView av1 = AlternateView.CreateAlternateViewFromString("<html><body><img src=cid:Logo/><br></body></html>" + strMailContent, null, MediaTypeNames.Text.Html);
av1.LinkedResources.Add(logo);
mailMessage.AlternateViews.Add(av1);
mailMessage.IsBodyHtml = true;
SmtpClient mailSender = new SmtpClient("localhost");
mailSender.Send(mailMessage);
}
catch (Exception e)
{
Console.WriteLine("Problem with email execution. Exception caught: ", e);
}
return;
}
}
}

You specify mailSender = new SmtpClient("localhost");.
Have you set up an SMTP server on your local machine? If not, you will need to do so to use SmtpClient. Otherwise, specify a hostname other than localhost, perhaps using your Gmail account as specified here, bearing in mind you will need to configure it for authentication and SSL.
See also the documentation for SmtpClient.
There are also one or two other issues I can see with your code - but let's deal with these after getting simple mail sending working.

if your problem is that you don't have a smtp server you are talking to on your machine, you will see an exception rather than just silently not having your email delivered (which i believe is what you are seeing given that you did not list an exception, but not completely sure). it could be that you are successfully delivering to your local smtp server, but it is failing to send the mail on. if you have the iis smtp server installed and that is what you are trying to use to send the mail, you can see failed email messages in the subdirectories of C:\Inetpub\mailroot. there is a badmail subdirectory that should have failed deliveries.
if you are on windows 7, it doesn't support the iis smtp server. an alternative for having an smtp server on your machine that doesn't actually deliver the email but does show you everything that has come through for any email address is http://smtp4dev.codeplex.com/. even if i do have the iis smtp server available in my operating system, i prefer this for development needs.