<?php

$mails = "birgit_dieltjens@hotmail.com
charlinehottlet@hotmail.com
els_frijters@hotmail.com
khalid.mahrous@gmail.com
cindy_vh@hotmail.com
raphaelwarolin@gmail.com";

$arr = explode("\n", $mails);

$output = '';

foreach($arr as $mail) {

$output .= trim($mail).',';

}

echo count($arr);

echo $output;

?>

6birgit_dieltjens@hotmail.com,charlinehottlet@hotmail.com,els_frijters@hotmail.com,khalid.mahrous@gmail.com,cindy_vh@hotmail.com,raphaelwarolin@gmail.com,