Using wp_mail in functions.php

Question

I have set up a simple mailer before I get the full implementation sorted. I've tried a few email addresses but am not receiving them even though it returns 'true'. I'm using wp_ajax as well if that makes a difference.

functions.php

    //  Check for email return in share folders
    add_action( 'wp_ajax_share_email', 'share_email' );
    add_action( 'wp_ajax_nopriv_share_email', 'share_email' );
    function share_email(){
        $email = $_POST['email'];
        // Return a boolean!
        $to = $email;
        $subject = "Test mail";
        $message = "Hello! This is a simple email message.";
        $from = "[email protected]";
        $headers = "From:" . $from;
        if(wp_mail($to,$subject,$message,$headers)) {
            return true;
        } else {
            return false;   
        }
    }

Can anyone let me know why this isn't sending? Am I not allowed to use wp_mail and wp_ajax together perhaps?

Thanks

EDIT Jquery part

    $('#share-pop .btn').click(function(){
        var email = check.val();
        jQuery.ajax({
            type: 'POST',
            url: ajaxurl,
            data: {"action" : "share_email", 'email': email},
            success: function(data){
                if (data) {
                    alert('sent');
                } else {
                    alert('An error occured');
                }
            }
        });
    });

Answer 1

You need to supply or line breaks for your header fields. For example:

$headers = "From:" . $from . PHP_EOL;

Or put the header fields into an array, in which case you don't need to add the line breaks manually.

$headers[] = "From:" . $from;

Email headers are not 'normal' text. Those line ending are meaningful. They are control characters.

There are examples in the Codex.

Answer 2

Correct me if I'm wrong here, but you're not receiving e-mails because you're not invoking the function on TRUE.

//  Check for email return in share folders
add_action( 'wp_ajax_share_email', 'share_email' );
add_action( 'wp_ajax_nopriv_share_email', 'share_email' );
function share_email(){
    $email = $_POST['email'];
    // Return a boolean!
    $to = $email;
    $subject = "Test mail";
    $message = "Hello! This is a simple email message.";
    $from = "[email protected]";
    $headers = "From:" . $from;
    if($to && $subject && $message && $headers) {
        wp_mail($to,$subject,$message,$headers);
    } else {
        return false;   
    }
}