I'm trying to send emails from a system that connects to internet through a http proxy which is set in Internet Options.
i'm using SmtpClient.
Is there any way to send mails with SmtpClient through this proxy setting.
Thanks
Http Proxies control http traffic, they rarely have anything to do with SMTP at all. I've never heard of proxying SMTP before after all SMTP itself is intrinsically supports a chain of "proxies" to the destination SMTP server.
I understand that you want to use the browsers default settings, i would also like an answer for that.
Meanwhile, you could do it manually.
MailAddress from = new MailAddress("from#mailserver.com");
MailAddress to = new MailAddress("to#mailserver.com");
MailMessage mm = new MailMessage(from, to);
mm.Subject = "Subject"
mm.Body = "Body";
SmtpClient client = new SmtpClient("proxy.mailserver.com", 8080);
client.Credentials = new System.Net.NetworkCredential("from#mailserver.com", "password");
client.Send(mm);
Use MailKit
From Microsoft:
Important
We don't recommend that you use the SmtpClient class for new
development because SmtpClient doesn't support many modern protocols.
Use MailKit or other libraries instead. For more information, see
SmtpClient shouldn't be used on GitHub.
Create a console app and add MailKit
dotnet new console --framework net6.0
dotnet add package MailKit
Code to send through proxy
using MailKit.Net.Proxy;
using MailKit.Net.Smtp;
using MailKit.Security;
using MimeKit;
var emailFromAddress = "myemail#gmail.com";
var token = "mytoken";
var to = "Someone.Else#gmail.com";
var message = new MimeMessage();
message.From.Add(new MailboxAddress("Me", emailFromAddress));
message.To.Add(MailboxAddress.Parse(to));
message.Subject = "test";
message.Body = new TextPart("plain")
{
Text = #"This is a test."
};
using (var client = new SmtpClient())
{
client.ProxyClient = new HttpProxyClient("my-proxy.mydomain.com", 80); // <-- set proxy
client.Connect("smtp.gmail.com", 587, SecureSocketOptions.StartTls);
client.Authenticate(emailFromAddress, token);
client.Send(message);
client.Disconnect(true);
}
In this example, I've used Gmail to send the email. To do so you have to generate a token.
Go to your gmail > click on your icon on the very top right of the page > Manage your Google Account > from the menu on the left choose Security > half way down choose App Passwords > select Mail and select your device > press Generate > copy the token and replace mytoken above.
If the only access you have to the internet is through HTTP, then pretty much the only way you'll be able to do this is by setting up a VPS (or equiv) with SSH on port 443 and using corkscrew (or putty) to tunnel ssh through. From there it is a simple matter to forward smtp traffic over your ssh tunnel.
Be aware that you may be violating the companies computing policy if you do this.
Related
I need send a mail from my program. Then I use MimeKit.
The problem is when run the program in another computer, with another email configurated by default.
So I need to use that default email on that computer.
My code is
var message = new MimeMessage();
message.From.Add(new MailboxAddress("CCCC", "cccc#xxxxx.com"));
message.To.Add(new MailboxAddress("KKKK", "kkkkkk#jjjjj.es"));
message.Subject = "¿Cómo estás?";
message.Body = new TextPart("plano")
{
Text = #"Kaixo Lorea"
};
using (var smtpClient = new SmtpClient())
{
smtpClient.Send(message);
}
I'm working with C# and Windows 10
Thanks
As far as I understand your question, you are asking how to read the SMTP server configuration settings from whatever email client program is configured on another system.
I doubt you'll have much luck with that.
I'm trying to set up some code to send email via Office 365's authenticated SMTP service:
var _mailServer = new SmtpClient();
_mailServer.UseDefaultCredentials = false;
_mailServer.Credentials = new NetworkCredential("test.user#mydomain.com", "password");
_mailServer.Host = "smtp.office365.com";
_mailServer.TargetName = "STARTTLS/smtp.office365.com"; // same behaviour if this lien is removed
_mailServer.Port = 587;
_mailServer.EnableSsl = true;
var eml = new MailMessage();
eml.Sender = new MailAddress("test.user#mydomain.com");
eml.From = eml.Sender;
eml.to = new MailAddress("test.recipient#anotherdomain.com");
eml.Subject = "Test message";
eml.Body = "Test message body";
_mailServer.Send(eml);
This doesn't appear to be working, and I'm seeing an exception:
The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM
at System.Net.Mail.MailCommand.Send(SmtpConnection conn, Byte[] command, String from)
at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, SmtpFailedRecipientException& exception)
at System.Net.Mail.SmtpClient.Send(MailMessage message)
I've tried enabling network tracing and it appears that secure communications are established (for example, I see a line in the log for the "STARTTLS" command, and later there's a line in the log "Remote certificate was verified as valid by the user.", and the following Send() and Receive() data is not readable as plain text, and doesn't appear to contain any TLS/SSH panics)
I can use the very same email address and password to log on to http://portal.office.com/ and use the Outlook email web mail to send and read email, so what might be causing the authentication to fail when sending email programmatically?
Is there any way to additionally debug the encrypted stream?
In my case after I tried all this suggestion without luck, I contacted Microsoft support, and their suggestion was to simply change the password.
This fixed my issue.
Note that the password wasn't expired, because I logged on office365 with success, however the reset solved the issue.
Lesson learned: don't trust the Office 365 password expiration date, in my case the password would be expired after 1-2 months, but it wasn't working.
This leaded me to investigate in my code and only after a lot of time I realized that the problem was in the Office365 password that was "corrupted" or "prematurely expired".
Don't forget every 3 months to "refresh" the password.
To aid in debugging, try temporarily switching to MailKit and using a code snippet such as the following:
using System;
using MailKit.Net.Smtp;
using MailKit.Security;
using MailKit;
using MimeKit;
namespace TestClient {
class Program
{
public static void Main (string[] args)
{
var message = new MimeMessage ();
message.From.Add (new MailboxAddress ("", "test.user#mydomain.com"));
message.To.Add (new MailboxAddress ("", "test.recipient#anotherdomain.com"));
message.Subject = "Test message";
message.Body = new TextPart ("plain") { Text = "This is the message body." };
using (var client = new SmtpClient (new ProtocolLogger ("smtp.log"))) {
client.Connect ("smtp.office365.com", 587, SecureSocketOptions.StartTls);
client.Authenticate ("test.user#mydomain.com", "password");
client.Send (message);
client.Disconnect (true);
}
}
}
}
This will log the entire transaction to a file called "smtp.log" which you can then read through and see where things might be going wrong.
Note that smtp.log will likely contain an AUTH LOGIN command followed by a few commands that are base64 encoded (these are your user/pass), so if you share the log, be sure to scrub those lines.
I would expect this to have the same error as you are seeing with System.Net.Mail, but it will help you see what is going on.
Assuming it fails (and I expect it will), try changing to SecureSocketOptions.None and/or try commenting out the Authenticate().
See how that changes the error you are seeing.
Be sure you're using the actual office365 email address for the account. You can find it by clicking on the profile button in Outlook365. I wrestled with authentication until I realized the email address I was trying to use for authentication wasn't the actual mailbox email account. The actual account email may have the form of: account#company.onmicrosoft.com.
We got ours working by converting the mailboxes (from address) from "shared" to "regular". Before this change, my application quit sending email when we migrated from Gmail to Office 365. No other code changes were required, besides setting the host to smtp.office365.com.
Please check below code I have tested to send email using Exchange Online:
MailMessage msg = new MailMessage();
msg.To.Add(new MailAddress("YourEmail#hotmail.com", "XXXX"));
msg.From = new MailAddress("XXX#msdnofficedev.onmicrosoft.com", "XXX");
msg.Subject = "This is a Test Mail";
msg.Body = "This is a test message using Exchange OnLine";
msg.IsBodyHtml = true;
SmtpClient client = new SmtpClient();
client.UseDefaultCredentials = false;
client.Credentials = new System.Net.NetworkCredential("XXX#msdnofficedev.onmicrosoft.com", "YourPassword");
client.Port = 587; // You can use Port 25 if 587 is blocked
client.Host = "smtp.office365.com";
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.EnableSsl = true;
try
{
client.Send(msg);
}
catch (Exception ex)
{
}
Port (587) was defined for message submission. Although port 587 doesn't mandate requiring STARTTLS, the use of port 587 became popular around the same time as the realisation that SSL/TLS encryption of communications between clients and servers was an important security and privacy issue.
In my case my problem was not related to the code but something to do with the Exchange mailbox. Not sure why but this solved my problem:
Go to the exchange settings for that user's mailbox and access Mail Delegation
Under Send As, remove NT AUTHORITY\SELF and then add the user's account.
This gives permissions to the user to send emails on behalf of himself. In theory NT AUTHORITY\SELF should be doing the same thing but for some reason that did not work.
Source: http://edudotnet.blogspot.com.mt/2014/02/smtp-microsoft-office-365-net-smtp.html
I got this same error while testing, using my own domain email account during development. The issue for me seemed related to the MFA (Multi Factor Authentication) that's enabled on my account. Switching to an account without MFA resolved the issue.
I had this issue since someone had enabled Security defaults in Azure.
This disables SMTP/Basic authentication. It's clearly stated in the documentation, but it's not evident by the error message, and you have to have access to the account to find out.
https://learn.microsoft.com/en-us/azure/active-directory/fundamentals/concept-fundamentals-security-defaults
It's possible to enable it per account.
https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/authenticated-client-smtp-submission
You need change the credentials function. Here is the substitution you need to make:
change
-*_mailServer.Credentials = new NetworkCredential("test.user#mydomain.com", "password");*
for this
-*_mailServer.Credentials = new NetworkCredential("test.user#mydomain.com", "password", "domain");*
In my case, password was expired.I just reset password and its started working again
I wrote up a sample program by copying the code in this KB article with some little edit as far as user's info. It uses the deprecate .NET library System.Web.Mail to do it because the new System.Net.Mail does not support implicit SSL. I went and tested it with Google smtp server on port 465 which is their implicit email port and everything works. However, when I gave this to a client to test it at his network, nothing get sent/receive, here is the error:
2013-03-07 15:33:43 - The transport failed to connect to the server.
2013-03-07 15:33:43 - at System.Web.Mail.SmtpMail.LateBoundAccessHelper.CallMethod(Object obj, String methodName, Object[] args)
2013-03-07 15:33:43 - at System.Web.Mail.SmtpMail.CdoSysHelper.Send(MailMessage message)
2013-03-07 15:33:43 - at System.Web.Mail.SmtpMail.Send(MailMessage message)
I'm not very well versed when it comes to email SSL so here is my possible theory to the root cause:
Assume he is using the right smtp server and right port (SSL port), I wonder if if any of the following could be the cause:
They are using SSL on the mail server and yet he does not have the certificate installed on the machine where he runs my program from even though he is on the same domain and use the same email domain as a sender.
They are using SSL but they maybe using NTLM or Anonymous authentication while my program uses basic authentication.
Sorry if I provide little information because I myself is quite foreign in this area so I'm still researching more.
Do you know of any steps I can do at my end to ensure my little test program can send using the smtp server of an implicit SSL email server?
Edit: I did add the following line in my code to indicates I'm using SSL.
oMsg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpusessl", "true");
Maybe this is to late to answer but have a look on https://sourceforge.net/p/netimplicitssl/wiki/Home/
You can send mail to port 465
Without the need of modifying your code, that much.
From the wiki page of project :
var mailMessage = new MimeMailMessage();
mailMessage.Subject = "test mail";
mailMessage.Body = "hi dude!";
mailMessage.Sender = new MimeMailAddress("you#gmail.com", "your name");
mailMessage.IsBodyHtml = true;
mailMessage.To.Add(new MimeMailAddress("yourfriend#gmail.com", "your friendd's name"));
mailMessage.Attachments.Add(new MimeAttachment("your file address"));
var emailer = new SmtpSocketClient();
emailer.Host = "your mail server address";
emailer.Port = 465;
emailer.EnableSsl = true;
emailer.User = "mail sever user name";
emailer.Password = "mail sever password" ;
emailer.AuthenticationMode = AuthenticationType.PlainText;
emailer.MailMessage = mailMessage;
emailer.OnMailSent += new SendCompletedEventHandler(OnMailSent);
//Send email
emailer.SendMessageAsync();
// A simple call back function:
private void OnMailSent(object sender, AsyncCompletedEventArgs asynccompletedeventargs)
{
Console.Out.WriteLine(asynccompletedeventargs.UserState.ToString());
}
Here I am using gmail smtp to send mail using c#. See the code below. It will give you an insight, How the stuffs are working. Replace gmail settings with your email server settings. Dont worry about the security certificates, they will be taken care of by the framework itself.
public static bool SendMail(string to, string subject, string body)
{
bool result;
try
{
var mailMessage = new MailMessage
{
From = new MailAddress("your email address")
};
mailMessage.To.Add(new MailAddress(to));
mailMessage.IsBodyHtml = true;
mailMessage.Subject = subject;
mailMessage.Body = body;
var userName = "your gmail username";
var password = "your gmail password here";
var smtpClient = new SmtpClient
{
Credentials = new NetworkCredential(userName, password),
Host = smtp.gmail.com,
Port = 587,
EnableSsl = true
};
smtpClient.Send(mailMessage);
result = true;
}
catch (Exception)
{
result = false;
}
return result;
}
The piece of code you were referencing was pretty old and obselete too. CDO was used in ASP apps to send mails. I think you havent scroll down to see
Article ID: 555287 - Last Review: April 7, 2005 - Revision: 1.0
APPLIES TO
Microsoft .NET Framework 1.1
You are refering a code that is pretty old... anyways follow the code shown up, everything will be FINE...
UPDATE
My bad, I have'nt read it carefully. But
I am leaving the above code as it is, as it might be a help for you
or any other guy, who need the mailing functionality via SSL over
gmail or any other server later.
. Then in such case you need some third party app.I found you a library See here
I am using this code to send an SMTP email via the yahoo SMTP server, it is for a personal project I am writing.
using System.Net.Mail;
using System.Net;
SmtpClient theClient = new SmtpClient("smtp.mail.yahoo.com", 465);
theClient.UseDefaultCredentials = false;
theClient.Credentials = new NetworkCredential("username", "password");
theClient.EnableSsl = true;
MailMessage theMessage = new MailMessage("username#yahoo.com",
"to.someone#gmail.com");
theMessage.Subject = "Dave test from C# subject";
theMessage.Body = "Dave test from C# body";
theClient.Send(theMessage);
It's all pretty standard code for sending SMTP email, but... the server seems to throw an error. It forcibly terminates the connection. This does not happen if I use other SMTP servers like Gmail, Windows Live or various other ISP Smtp servers.
This is the exception and stack trace:
System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at ConsoleApplication1.Program.Main(String[] args) in E:\dev\ARCSoftware.FTPProcessor\ConsoleApplication1\Program.cs:line 28
I know the problem is not environmental though as I can send to the same server with these exact settings using Outlook Express. I am wondering if I need to send a certificate or something?
If you, or anyone you know where has any ideas about this I would greatly appreciate some help.
using System.Net.Mail;
using System.Net;
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void btn_Send_Click(object sender, RoutedEventArgs e)
{
MailMessage oMail = new MailMessage(new MailAddress("username#yahoo.com"), new MailAddress("username#yahoo.com"));
SmtpClient oSmtp = new SmtpClient();
oSmtp.Host = "smtp.mail.yahoo.com";
oSmtp.Credentials = new NetworkCredential("username", "password");
oSmtp.EnableSsl = false;
oSmtp.Port = 587;
oSmtp.Send(oMail);
}
}
It's not supported through 465, but the following post details a workaround
How can I send emails through SSL SMTP with the .NET Framework?
UPDATE: This link details why it might work through Outlook Express, but not through the System.Net.Mail
http://blogs.msdn.com/b/webdav_101/archive/2008/06/02/system-net-mail-with-ssl-to-authenticate-against-port-465.aspx
Port 465 isn't supported by System.Net.Mail.SmtpClient.
http://msdn.microsoft.com/en-us/library/system.net.mail.smtpclient.enablessl.aspx
From the Remarks Section:
This connection method is sometimes called SMTP/SSL, SMTP over SSL, or SMTPS and by default uses port 465. This alternate connection method using SSL is not currently supported.
Edit:
You could try using port 587 instead (if Yahoo supports it).
I had the same problem until I set the port to 587 and disabled SSL.
I think you should revert to using System.Web.Mail which lets you control fields that are not accessible through the newer System.Net.
Try to play with those. For instance you could try this:
(use is documented here, fields are documented here)
MailMessage msg = new MailMessage();
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpserver", "smtp.mail.yahoo.com");
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpserverport", "465");
// try "2", I have not tested for yahoo mail
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusing", "2");
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpusessl", "1");
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); // 0= anonymous - 1=basic - 2=NTLM
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "yahoousername");
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "yahoopwd");
I'm trying to send an email message using the .NET MailMessage class which can also have the return-path header added so that any bounces come back to a different email address. Code is below:
MailMessage mm = new MailMessage(
new MailAddress(string.Format("{0}<{1}>", email.FromName, email.FromEmail)),
new MailAddress(emailTo));
mm.Subject = ReplaceValues(email.Subject, nameValues);
mm.ReplyTo = new MailAddress(string.Format("{0}<{1}>", email.FromName, email.FromEmail));
mm.Headers.Add("Return-Path", ReturnEmail);
// Set the email html and plain text
// Removed because it is unneccsary for this example
// Now setup the smtp server
SmtpClient smtp = new SmtpClient();
smtp.Host = SmtpServer;
smtp.DeliveryMethod = SmtpDeliveryMethod.PickupDirectoryFromIis;
if (SmtpUsername.Length > 0)
{
System.Net.NetworkCredential theCredential =
new System.Net.NetworkCredential(SmtpUsername, SmtpPassword);
smtp.Credentials = theCredential;
}
smtp.Send(mm);
Whenever I check the email that was sent I check the header and it always seems to be missing return-path. Is there something I am missing to configure this correctly? As I said above I'm using the standard Virtual Mail Server on my development machine (XP) however it will run on Windows 2003 eventually.
Has anyone got any ideas why it isn't coming through?
The Return-Path is set based on the SMTP MAIL FROM Envelope. You can use the Sender property to do such a thing.
Another discussion on a related issue you will have sooner or later: How can you set the SMTP envelope MAIL FROM using System.Net.Mail?
And btw, if you use SmtpDeliveryMethod.PickupDirectoryFromIis, the Sender property is not used as a MAIL FROM; you have to use Network as a delivery method to keep this value.
I did not find any workaround for this issue.
PickupDirectoryFromIis, Sender property and SMTP MAIL FROM envelope