that was really a good idea!
i configured a little bit.
here is what is working now!
ip=`ifconfig -a ppp0 | grep "inet addr" | cut -f2 -d ":" | cut -f1 -d "P"`
echo
ftp://USERNAME:PASSWORT@$ip > ip.txt
mail
mail@whoever.com < ip.txt
so you just don`t need a fix ip anymore!