CreateUserWizard SendingMail Event Not Firing

Hi
I am using CreateUserWizard and want to make email verification on user registration.
But CreateUserWizard1_SendingMail event is not firing.
<asp:CreateUserWizard ID="CreateUserWizard1" runat="server"
 OnCreatedUser="CreateUserWizard1_CreatedUser"
 OnSendingMail="CreateUserWizard1_SendingMail"
 MailDefinition-BodyFileName="~/VerifyEMail/NewAccount.htm"
 MailDefinition-From="abc@xyz.net"
 MailDefinition-IsBodyHtml="true"
 MailDefinition-Priority="High"
 MailDefinition-Subject="activate new account."
 ContinueDestinationPageUrl="~/Default.aspx"
 CancelDestinationPageUrl="~/Default.aspx"
 DisableCreatedUser="True" >
      
Code-Behind&nbs ...