[exim] newbie - error 550 relay not permitted

Hi,

I've configured well my account to can send mail from my ubuntu to external
accounts. I only have to install exim and modify a file called
passwd.client.

Everythink it's ok but when I try to configure to put my SMPT ISP Server, I
change the passwd.cleint writing the line:
smtp.gmail.com:peluca35@???:L3qwpok3

it gives me an error when I try to send a mail:

2010-01-07 11:51:35 1NSpxn-00014X-T0 <= david@localhost U=david P=local
S=311
2010-01-07 11:51:36 1NSpxn-00014X-T0 ** hola@localhost: Unrouteable address
2010-01-07 11:51:46 1NSpxn-00014X-T0 ** pepelu@??? R=smarthost
T=remote_smtp_smarthost: SMTP error from remote mail server after RCPT
TO:<davidtuti@
gmail.com>: host smtp.jazztel.es [62.14.3.192]: 550 relay not permitted
2010-01-07 11:51:47 1NSpxy-00014c-VH <= <> R=1NSpxn-00014X-T0 U=Debian-exim
P=local S=1260

Could you help me please?
Many thanks and sorry for my english!