WP Ajax Function Always Returning undefined

Per @SallyCJ suggestion to use await I construed this new function

async function doAjax(email) {
    let result;

    try {
        result = await jQuery.ajax({
            url: ajaxurl,
            type: 'POST',
            data: {"action": "custome_ajax_email_check", "guestemail": email }
        });

        return result;
    } catch (error) {
        console.error(error);
    }
}

Then my validate() function now just is simply

function validate() {
    var email = jQuery("#billingemail").val();

    if (isValidEmailAddress(email)) {
        doAjax(email).then( (data) => ajaxCallResult(data) )
    }

  . . . . . 

Then lastly

function ajaxCallResult(data){

    data = jQuery.parseJSON(data);
 
  . . . . . . 

It is working.. very interesting, learning about await then, asynchronous and synchronous calls, etc