Ask for allow popup before sending mail

Here is an example of how you can ask for permission to send a popup before sending an email:

// Get the user's permission to send the email
if (confirm("Do you want to send an email?")) {
  // Send the email
  //...
} else {
  // Cancel the email sending
  //...
}

This code uses the confirm() function to display a popup dialog box that asks the user if they want to send the email. If the user clicks "OK", the code inside the if statement will be executed, which in this case would be sending the email. If the user clicks "Cancel", the code inside the else statement will be executed, which in this case would be canceling the email sending.

You can also use prompt() function to ask for permission, it will allow you to get more information from the user, like the email subject and body.

var subject = prompt("Enter the email subject:");
var body = prompt("Enter the email body:");

if (confirm("Do you want to send an email with subject '" + subject + "' and body '" + body + "'?")) {
  // Send the email
  //...
} else {
  // Cancel the email sending
  //...
}

You can also use alert() function to ask for permission, but it's not recommended because it's not as interactive as confirm() or prompt().

if (confirm("Do you want to send an email?")) {
  // Send the email
  //...
} else {
  // Cancel the email sending
  //...
}

It's worth noting that this is a simple example, in a real-world scenario you would want to handle the user's response more robustly, and also you would want to validate the user's input before sending the email.