As it says in the title, I wish to change the FROM address provided to the SMTP server, as opposed to the FROM address in the email envelope.
The closest sample I can find is from Java, which is can be found here
Thanks
Bottom line is, you can't do this. The FROM address used in System.Net.Mail is used for both the SMTP transaction (Envelope-From) and the MailMessage from header value.
Sorry,
Dave
The FROM provided to the SMTP server is the login of the SmtpClient while the one in the Mail is the FROM in the MailMessage.
SmtpClient smtp = new SmtpClient();
smtp.Host = "myserver.address.com";
smtp.Credentials = new NetworkCredential("me#server.com", "myPassword");
MailMessage msg = new MailMessage();
msg.From = "otherMe#server.com";
//OTHER MESSAGE SETTINGS
smtp.Send(msg);
This should send an e-mail from "otherMe#server.com" using the authentication on the server for the user "me#server.com"
The Java example is about return address, not From.
As Far as I know, you can't do this. SMTP servers use the From address to decide if the want to relay or not.
The only other credential you've got is the Login to the SMTP server.
Unfortunately, this is not possible.
First there is a syntax error for smtp.Host = smtp.serv.com; This is not valid written string type, and the second thing is that the property Host doesn't exist.
As explained by bzlm, if you're using Network delivery method of SmtpClient, then you can set MAIL FROM by setting the MailMessage.Sender property. Note, however, that this will have the side-effect of adding a Sender heady to your message, which will cause many email clients to display present the message sender as "X on behalf of Y".
Related
Some say it's impossible to verify that an email exists, but I also read it can be done by sending a message to it. So I want to verify if the email exists or not by sending it email.
Here is my code:
private void email_checker()
{
MailMessage mm = new MailMessage();
//The email that needs to be checked
mm.To.Add(new MailAddress(txtEmailAddress.Text, "Email Check"));
mm.From = new MailAddress("*******#gmail.com");
mm.Body = "Verified";
mm.IsBodyHtml = true;
mm.Subject = "Verification";
SmtpClient smc1 = new SmtpClient();
smc1.Host = "smtp.gmail.com";
smc1.Port = 587;
smc1.Credentials = new NetworkCredential("*****#gmail.com","********");
smc1.EnableSsl = true;
smc1.Send(mm);
}
This code is functioning, but I tried to type any random email that does not exist (it really does not exist) and the code still sends a message to it. I wanted to create a popup message that prompts whenever the message has failed to sent in that way I'll know that the email really does not exist. Or is there really no other way than sending a verification link?
There is no way to see if an email exists. Remember that your code used to send an email is asking an SmtpClient to send the email. You will only get an exception if the client's server throws one. The client's server in your case is GMail. GMail doesn't fail on sending, but replies back to the sender that the email address wasn't found. Different servers behave differently. You can setup your own server to automatically retry emails or just fail silently or throw an exception, etc. Also, servers use dns so it's possible to have an intranet mail system where the email is valid to the network, but not the internet. Another thing to keep in mind is the catch all email addresses that can be setup. So the email address in question may not be valid, but caught by the catch all and then delivered to the valid address.
So, no possible way, as of now, to validate the existence of an email address.
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
var client = new SmtpClient("smtp.gmail.com", 587)
{
Credentials = new NetworkCredential("mail#gmail.com", "supersecretpassword"),
EnableSsl = true
};
MailMessage message = new MailMessage(new MailAddress(sender),
new MailAddress(recepient));
//message.From = new MailAddress(sender);
message.IsBodyHtml = true;
// message.To.Add(new MailAddress(recepient));
//message.ReplyToList.Add(new MailAddress(sender));
message.Subject = "subject";
message.Body = "title";
client.Send(message);
I'm sending an email using the code above, however, if the recepient decides to reply to the email, i want the to reply to the Adress supplied in the sender parameter, but when i receive the email, the From field gives the address of the mail#gmail.com provided in the smtp info.
I tried setting the replyto, replytolist and from properties in MailMessage, but it doesn't cahnge anything.
With the reply to i could see the sender address in "ReplyTo" in gmail, but the default receiver if i pressed reply is still mail#gmail.com
Am i not supposed to be able to change this for some reason, or am i missing something?
EDIT
i'm suspecting this has to do with using a temporary gmail as smtp server, but i can't find any confirmation to this.
ReplyTo is deprecated, ReplyToList is a correct way.
If you think this is a gmail related problem try with another smtp (for example sendgrid )
Keep in mind that gmail uses Sender and From differently in case of "fake" account as you can read here
https://stackoverflow.com/a/3872880/744610
according to this answer it is because i'm using gmail as smtp server, and gmail doesn't allow changing the From/sender properties of an email, to avoid spam
I am using the following very simple code and I keep getting System.Net.Mail.SmtpException failure sending mail. This is my code:
static void main(string[] args)
{
MailAddress from = new MailAddress("MyEmail#gmail.com", "Mr. Test");
MailAddress to = new MailAddress("AnotherEmail#gmail.com", "mr. man");
MailMessage msg = new MailMessage(from, to);
msg.Subject = "email";
msg.Body = "This is email.";
SmtpClient client = new SmtpClient("smtp.gmail.com");
client.Send(msg);
}
I have never tried programmatically sending email before so I appreciate the help.
You're missing credentials and sending as TLS (secured connection):
Credentials = new NetworkCredential("myusername#gmail.com", "mypwd"),
EnableSsl = true
More Details here:
Sending email through Gmail SMTP server with C#
First thing I see incorrect with the code given is there is no username/password given for validation with the smtp server.
Also, to get a better idea of what exactly is causing the SmtpException, catch the exception in your debugger and look at the details of the exception. I've gotten good explanations of what is causing SMTP errors by doing this.
You can try following these directions to send mail using SMTP via gmail. http://blogs.msdn.com/b/mariya/archive/2006/06/15/633007.aspx
Google does not want you to use port 25, they want you to use 587 (ssl) or 467. They also require that you authenticate when sending mail.
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