Ubuntu :: Endless Script Running At Startup Safe?

Sometimes I need remotely connect to my computer, but my router gains IP address dynamically. So I wrote simple script which gains my router IP and send me email:

Code:
#!/bin/bash
function send_mail {
echo $1 | mutt -s "New IP" myemail.com
}
old_ip=
while true; do
new_ip=`wget www.whatismyip.com/automation/n09230945.asp -O - -q`
if [ -n "$new_ip" ] && [ "$new_ip" != "$old_ip" ];
then
old_ip=$new_ip
send_mail "IP changed, sending new IP: $new_ip"
fi
sleep 5m
done

I need it to run at system startup. When I'm adding it to .bash_profile bash path/resolveIP & I'm not getting any mail. In case of bash path/resolveIP (without &) I'm getting mail, but I guess it will never get to the next command in .bash_profile. So I put my script in /etc/init.d directory, but I don't know is it okay to have endless script there????