Export (0) Print
Expand All
6 out of 21 rated this helpful - Rate this topic

SmtpClient.Credentials Property

Gets or sets the credentials used to authenticate the sender.

Namespace:  System.Net.Mail
Assembly:  System (in System.dll)
public ICredentialsByHost Credentials { get; set; }

Property Value

Type: System.Net.ICredentialsByHost
An ICredentialsByHost that represents the credentials to use for authentication; or null if no credentials have been specified.
ExceptionCondition
InvalidOperationException

You cannot change the value of this property when an email is being sent.

Some SMTP servers require that the client be authenticated before the server will send e-mail on its behalf. To use your default network credentials, you can set the UseDefaultCredentials to true instead of setting this property. If the UseDefaultCredentials property is set to false, then the value set in the Credentials property will be used for the credentials when connecting to the server. If the UseDefaultCredentials property is set to false and the Credentials property has not been set, then mail is sent to the server anonymously.

Credentials information can also be specified using the application and machine configuration files. For more information, see <mailSettings> Element (Network Settings). If information is specified using the Credentials property, this information overrides the configuration file settings.

Caution noteCaution

If you provide credentials for basic authentication, they are sent to the server in clear text. This can present a security issue because your credentials can be seen, and then used by others.

The following code example demonstrates setting the credentials used to send an e-mail.


		public static void CreateTestMessage1(string server, int port)
		{
			string to = "jane@contoso.com";
			string from = "ben@contoso.com";
			string subject = "Using the new SMTP client.";
			string body = @"Using this new feature, you can send an e-mail message from an application very easily.";
			MailMessage message = new MailMessage(from, to, subject, body);
			SmtpClient client = new SmtpClient(server, port);
			// Credentials are necessary if the server requires the client 
			// to authenticate before it will send e-mail on the client's behalf.
			client.Credentials = CredentialCache.DefaultNetworkCredentials;

      try {
			  client.Send(message);
      }
			catch (Exception ex) {
			  Console.WriteLine("Exception caught in CreateTestMessage1(): {0}", 
                    ex.ToString() );
      }              
		}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Did you find this helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

ADD
Show:
© 2014 Microsoft. All rights reserved.