Exchange receipients.sh

 #!/bin/sh

 ### The minimal lines virtual.txt must have to generate the db
 MINLINES="50"
 ### The url to the receipients file
 URL=""

 wget "$URL" -qO /tmp/virtual.txt

 if [ -f /tmp/virtual.txt ]; then
    LINES=`cat /tmp/virtual.txt | wc -l`
    if [ "$LINES" -gt "$MINLINES" ]; then
       dos2unix /tmp/virtual.txt

       sed '/^\#/d; /^$/d' /tmp/virtual.txt > /etc/postfix/exchange_receipients
       postmap /etc/postfix/exchange_receipients
    fi
 fi