SmtpClient.Credentials Property

Reference

Definition

Namespace:: System.Net.Mail

Assembly:: System.Net.Mail.dll

Assembly:: System.dll

Assembly:: netstandard.dll

Source:: SmtpClient.cs

Source:: SmtpClient.cs

Source:: SmtpClient.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Gets or sets the credentials used to authenticate the sender.

public:
 property System::Net::ICredentialsByHost ^ Credentials { System::Net::ICredentialsByHost ^ get(); void set(System::Net::ICredentialsByHost ^ value); };

public System.Net.ICredentialsByHost? Credentials { get; set; }

public System.Net.ICredentialsByHost Credentials { get; set; }

member this.Credentials : System.Net.ICredentialsByHost with get, set

Public Property Credentials As ICredentialsByHost

Property Value

ICredentialsByHost

An ICredentialsByHost that represents the credentials to use for authentication; or null if no credentials have been specified.

Exceptions

InvalidOperationException

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

Examples

The following code example demonstrates setting the credentials used to send an email.

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

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 email 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 email on the client's behalf.
    client.Credentials = CredentialCache.DefaultNetworkCredentials;
    client.Send(message);
}

Remarks

Some SMTP servers require that the client be authenticated before the server will send email 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

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.

Applies to

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