wp_mail not working from Apple computers

I have a simple mail script that sends an email with form information to myself just before the form gets submitted to another location. Everything works fine as long as the user who fills out the form is on a PC. It doesn’t work if the user is on a mac. Using this code:
add_action(‘wp_ajax_nopriv_mail_before_submit’, ‘send_AJAX_mail_before_submit’);
in functions.php. The mail sendingg code is in send_AJAX_mail_before_submit routine. I am using bluehost and their support had no clues for me. I have scoured the web for solutions with no results. Here’s the snippet of code:
$headers =
‘Return-Path: ‘ . $emailfrom . “\r\n” .
‘From: ‘ . $fromname . ‘ <‘ . $emailfrom . ‘>’ . “\r\n” .
‘X-Priority: 3’ . “\r\n” .
‘X-Mailer: PHP ‘ . phpversion() . “\r\n” .
‘Reply-To: ‘ . $fromname . ‘ <‘ . $emailfrom . ‘>’ . “\r\n” .
‘MIME-Version: 1.0’ . “\r\n” .
‘Content-Transfer-Encoding: 8bit’ . “\r\n” .
‘Content-Type: text/plain; charset=UTF-8’ . “\r\n”;
$params = ‘-f ‘ . $emailfrom;
wp_mail($emailto, $subject, $msgBody, $headers, $params);