Getting Error- Invalid mail Attachment - asp.net

Question

I am trying to send email with excel file attachment. But getting invalid mail attachment error.
Please help me.
Here is my code-

Answer 1

Here is code for Email sending-
protected void btnSend_Click(object sender, EventArgs e)
{
System.Net.Mail.MailMessage msg = new System.Net.Mail.MailMessage();
msg.From = new MailAddress(txtFrom.Text);
msg.To.Add(txtTo.Text);
msg.Subject = txtSubject.Text;
if (FileUpload1.HasFile)
{
String FileName = FileUpload1.PostedFile.FileName;
MailAttachment mailAttachment = new MailAttachment(FileName, MailEncoding.Base64);
// msg.Attachments.Add(mailAttachment);
msg.Attachments.Add(mailAttachment);
}
using (SmtpClient client = new SmtpClient())
{
client.EnableSsl = true;
client.UseDefaultCredentials = false;
client.Credentials = new NetworkCredential(txtFrom.Text, txtPassword.Text);
client.Host = "smtp.gmail.com";
client.Port = 587;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.Send(msg);
}
}

Answer 2

Right click on project name in solution explorer . Click on Add then Choose new folder name it MailDocuments. Use this code to Save it and Attach It.
if (FileUpload1.HasFile)
{
string fileName = FileUpload1.PostedFile.FileName;
string Path = Server.MapPath("~/MailDocuments/");
FileUpload1.PostedFile.SaveAs(Path + fileName);
MailAttachment ma = new MailAttachment(Server.MapPath("~/MailDocuments/" + fileName), MailEncoding.Base64);
msg.Attachment.Add(ma);
}
private bool SendEmail(string myIPAddress)
{
bool emailsent = true;
if (myemailaddress != "" && mypassword != "")
{
System.Net.Mail.MailMessage mail = new System.Net.Mail.MailMessage();
mail.To.Add(myemailaddress);
mail.CC.Add("whoever#yahoo.com");
mail.From = new MailAddress("do.not.reply#whatever.com", "do.not.reply#whatever.com", System.Text.Encoding.UTF8);
mail.Subject = "Type Subject Here";
mail.SubjectEncoding = System.Text.Encoding.UTF8;
mail.Body = "Your IP address has changed to " + myIPAddress;
mail.BodyEncoding = System.Text.Encoding.UTF8;
mail.IsBodyHtml = true;
mail.Priority = MailPriority.High;
SmtpClient client = new SmtpClient();
client.Credentials = new System.Net.NetworkCredential("yourGmailEmail#gmail.com", "thepasswordforthataccount");
client.Port = 587; // Gmail works on this port
client.Host = "smtp.gmail.com";
client.EnableSsl = true; //Gmail works on Server Secured Layer
try
{
client.Send(mail);
}
catch (Exception ex)
{
emailsent = false;
}
}
else
{
emailsent = false;
}
return emailsent;
}