Question

   public void Form1_Load(Object sender, EventArgs e) 
    {
          // Other initialization code
         mtxtEmailID.Mask = ".........."; 

what should be the Mask Type in place of dots

         mtxtEmailID.MaskInputRejected += new MaskInputRejectedEventHandler(mtxtEmailID_MaskInputRejected)
    }

   void mtxtEmailID_MaskInputRejected(object sender, MaskInputRejectedEventArgs e)
   {
      if(!Regex.IsMatch(txtEmailID.Text, "^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$"))  

the regex here gives me error, let me know what is the right one for email validation.

         {
         toolTip1.ToolTipTitle = "Invalid Input";
         toolTip1.Show("Enter valid email address", mtxtEMailID);
         }
   }

Answer 1

You can find info about MaskedTextBox here

---

If you want to validate an Email Address Regex is not the right choice.There are many corner cases that the regex wont cover…

Use MailAddress

try 
{
   address = new MailAddress(address).Address;
   //email address is valid since the above line has not thrown an exception
} 
catch(FormatException) 
{
   //address is invalid
}

---

But if you need regex, it should be:

.+@.+