SmtpClient.MailFrom Method

Sends the MAIL command.

[Visual Basic]
Public Sub MailFrom( _
ByVal sender As String, _
ByVal parameters As String _
)

[C#]
public void MailFrom(
string sender,
string parameters
);

Parameters

sender: The sender argument of the MAIL command.
parameters: The optional command parameters of the MAIL command. The value may be null or an empty String.

Remarks

The MAIL command begins a mail transaction, and tells the SMTP server the sender of the current message.

Various SMTP extensions permit optional parameters to the MAIL command. One of the most useful extensions is the SIZE extension defined in RFC 1870. The SIZE extension allows the client to report the size of a message to the server before it sends the message. The server may then reject a message that is too large. (The alternative is for the server to reject the message after the message is sent!)

The MailFrom method takes the sender email address as a required parameter, and a list of MAIL command parameters as an optional parameter. The sender string should be a simple email address in the form "jdoe@example.org". The parameters string should contain the MAIL command parameters as they would be sent in the MAIL command line. parameters may be null or an empty string.

            String sender = "jdoe@example.org";
            String parms = String.Format("SIZE={0}", messageSize);
            smtpClient.MailFrom(sender, parms);

After the method returns, you should check the server's reply code, available as the ReplyCode property. A 250 reply code indicates success.

Note: The "sender" is considered part of the SMTP envelope, and may be different from the "From" header field of the actual message. The SMTP envelope sender is associated with message delivery, indicating a return address ("return path") for delivery status notifications.

Exceptions

Exception Type	Condition
Exception	If a network or protocol error occurs.

SmtpClient.MailFrom Method

Parameters

Remarks

Exceptions

See Also