I am using the below code to send email having an attachment , but mails are not being received in Zoho account . The code works fine as I am able to receive mails in gmail though its going to spam folder

$output = '<h1>Thanks for your file and message!</h1>';

        //Set the form flag to no display (cheap way!)

        $flags = 'style="display:none;"';

        //Deal with the email

        $to = ' ashokbugude@gmail.com';

        $subject = 'a file for you';

        $msg = strip_tags($_POST['message']);

        $filename = $_FILES['file']['name'];

        $boundary =md5(date('r', time())); 

        $headers = "From: info@zayyon.com\r\nReply-To: info@zayyon.com";

        $headers .= "\r\nMIME-Version: 1.0\r\nContent-Type: multipart/mixed; boundary=\"_1_$boundary\"";

        $msg="This is a multi-part message in MIME format.

--_1_$boundary

Content-Type: multipart/alternative; boundary=\"_2_$boundary\"

--_2_$boundary

Content-Type: text/plain; charset=\"iso-8859-1\"

Content-Transfer-Encoding: 7bit

$message

--_2_$boundary--

--_1_$boundary

Content-Type: application/octet-stream; name=\"$filename\" 

Content-Transfer-Encoding: base64 

Content-Disposition: attachment 

$attachment

--_1_$boundary--";

         $ok = mail($to, $subject, $msg, $headers);

          if($ok) {

    echo "You file has been sent

    to the email address you specified.

    Make sure to check your junk mail!

    Click here to return to mysite.com.";

    } else {

    die("Sorry but the email could not be sent. Please go back and try again!");

    }