My ddclient gives me this error when trying to update my dns.
"RECEIVE: badauth
FAILED: updating delwin.dynu.com&alias=ALIAS: badauth: Bad authorization (username or password)"

this is my ddclient config file.

# ddclient configuration for Dynu
#
# /etc/ddclient.conf
daemon=60 # Check every 60 seconds.
syslog=yes # Log update msgs to syslog.
mail=root # Mail all msgs to root.
mail-failure=root # Mail failed update msgs to root.
pid=/var/run/ddclient.pid # Record PID in file.
use=web, web=checkip.dynu.com/, web-skip='IP Address' # Get ip from server.
server=api.dynu.com # IP update server.
protocol=dyndns2
login=(tried both short name and email address) # Your username
password=XXXXX # Your password or MD5 of password
delwin.dynu.com&alias=ALIAS # Update IP address for alias of your domain name

where do i fail ?

Please change this line delwin.dynu.com&alias=ALIAS to the following:

delwin.dynu.com