SMTP サーバー経由でメールを送信しようとすると、例外が発生します。例外は次のとおりです。
System.Net.Mail.SmtpException: Transaction failed.
The server response was: 5.7.7 Sender Unknown in Local Domain . at
System.Net.Mail.MailCommand.CheckResponse(SmtpStatusCode statusCode, String response) 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) at _Default.Button1_Click1(Object sender, EventArgs e)
in d:\pjt\mail_check\Default.aspx.cs:line 39