I am trying to send an email via SmtpClient ("smtp.office365.com") and am running into issues.
Consider the following code snippet:
var fromAddress = new MailAddress("someone#example.com", "TestFrom");
var toAddress = new MailAddress("someoneto#example.com", "TestSend");
string fromPassword = "SomePassword";
var smtp = new SmtpClient
{
Host = "smtp.office365.com",
Port = 587,
EnableSsl = true,
DeliveryMethod = SmtpDeliveryMethod.Network,
UseDefaultCredentials = false,
Credentials = new NetworkCredential(fromAddress.Address, fromPassword)
};
using (var message = new MailMessage(fromAddress, toAddress)
{
Subject = "Hey There Did this Test Work?",
Body = "Hey There Did this Test Work?",
IsBodyHtml = true,
})
smtp.Send(message);
This code works correctly from a .Net console application.
I can also use the same credentials and send an email via PowerShell.
When I attempt to use the same code snippet in an Asp.Net application, it fails.
I've tried this with the application deployed locally and to Azure.
I get the same results.
I get the following exceptions:
Failure sending mail. Unable to read data from the transport
connection: net_io_connectionclosed.
I am told that used to work correctly at some point previous to the past 3 months.
Am I doing something wrong here? Are there additional configuration settings I should be using? Does Asp.Net require something to bet set up (locally and within Azure) in order for this to work?
Thx
We had similar issues sending emails and it turned out that it was because we weren't enforcing TLS 1.2. You can enforce it with following code:
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
You only need call it once in your application, so Application_Start callback in global.asax is one possible place to put it.
Related
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.
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;
I am trying to send emails through Outlook 365. I get the following error.
SMTP Error: [MustIssueStartTlsFirst]
Message: The SMTP server requires a secure connection or the client was not authenticated.
My code:
System.Net.NetworkCredential cred = new System.Net.NetworkCredential(mailInfo.FromAddr, mailInfo.Password);
SmtpClient mailClient = new SmtpClient(mailInfo.Server) {
Port = mailInfo.Port,
EnableSsl = true, //mailInfo.SSL,
DeliveryMethod = SmtpDeliveryMethod.Network,
UseDefaultCredentials = false,
Credentials = cred,
TargetName = "STARTTLS/smtp.office365.com"
};
MailMessage message = new MailMessage {
From = new MailAddress(mailInfo.FromAddr, mailInfo.FromName),
Subject = "Manifest Processor Shipment Report - Manifest: " + shipment.ManifestNumber,
Body = BuildManifestEmailBody(shipment),
Priority = MailPriority.High,
IsBodyHtml = true
};
What is strange, is I have a small test program that runs, using the same code.
See Outlook Mail REST API reference in MSDN. The Outlook Mail API lets you read, create, and send messages and attachments, view and respond to event messages, and manage folders in a user's mailbox in Office 365 or Exchange Online.
Also you may find EWS helpful. See EWS Managed API, EWS, and web services in Exchange for more information.
This question already has answers here:
Gmail Error :The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required
(21 answers)
Closed 7 years ago.
This is my code
private void sendEmail()
{
var fromAddress = new MailAddress("gmail email", "name");
var toAddress = new MailAddress("email", "name");
const string fromPassword = "password";
const string subject = "ERROR";
var smtp = new SmtpClient
{
Host = "smtp.gmail.com",
Port = 587,
EnableSsl = true,
DeliveryMethod = SmtpDeliveryMethod.Network,
Credentials = new NetworkCredential(fromAddress.Address, fromPassword),
UseDefaultCredentials = false,
Timeout = 20000
};
using (var message = new MailMessage(fromAddress, toAddress)
{
Subject = subject,
Body = "this is an example",
})
{
smtp.Send(message);
}
}
When I debug the application, it will stop at the smtp.Send(message) and display an error message of " The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required? "
What should I do? Sometimes it works, sometimes it doesn't.
There are multiple possibility in which you can face this issue. Check following things
1) Recheck if you are giving correct email and password.
2) Check if you have two step validation for your GMail account.
3) At times Gmail stops sending mails so log-in you gmail account and and it might start working.
4) In case you have issue of Location issue like your gmail account and production server have different times zone refer this link.
Access for less secure apps Link.
Hope once of this will help you.
I have read other answers on the stackoverflow. but none of the solutions work for me.
I'm trying to send email through live.com, but unable to it.
The error message:
mailbox unavailable. The server response was: 5.7.3 requested action aborted;
user not authenticated
or error message:
System.Net.Mail.SmtpException: Service not available,
closing transmission channel.
The server response was: Cannot connect to SMTP server 65.55.176.126
(65.55.176.126:587), NB connect error 1460
The code:
MailMessage mail = new MailMessage();
mail.From = new MailAddress("email#live.com");
mail.To.Add("someone#someone.com");
mail.Subject = "hello";
mail.Body = "awefkljj kawefl";
mail.IsBodyHtml = false;
SmtpClient smtp = new SmtpClient("smtp.live.com", 587);
smtp.EnableSsl = true;
smtp.Credentials = new NetworkCredential("email#live.com", "password");
smtp.Send(mail);
Are you able to send the email by using above code?
It works before, last year, but it is no more working now.
I'm not sure what has been changed to live.com email server.
What new settings or parameters should apply?
I ran into an issue where I was unable to send emails using the smtp.live.com SMTP server from certain hosts -- particulary Azure hosts. In my case, the SMTP attempt was from a host that I had never used to sign-in previously, so the attempt was blocked with the 5.7.3 error:
Mailbox unavailable. The server response was: 5.7.3 requested action aborted; user not authenticated
The solution was to browse to the account settings, locate the SMTP request in its recent activity, and select "This was me":
Tested and it works (different host address and a few other property set):
using (var client = new SmtpClient("smtp-mail.outlook.com")
{
Port = 587,
DeliveryMethod = SmtpDeliveryMethod.Network,
UseDefaultCredentials = false,
EnableSsl = true,
Credentials = new NetworkCredential(_sender, _password)
})
{
using (var mail = new MailMessage(_sender, _recipient)
{
Subject = _subject,
Body = _message
})
{
client.Send(mail);
}
}
Also, if the account has two-step verification turned on, you'll have to generate an app password and use that instead.
Your code works for me without any changes with a live.com address. I am able to generate the same exception by simply putting an incorrect password.
I would suggest following checks:
Did the user change password recently? Are you able to login with the credentials provided over the web interface?
if yes, does your program uses the exact same credentials? please note that white space can be your enemy.