[Exim] need help with smtp-auth client (exim4)

i have fetchmail set up to contact my isp and grab my emails and dump
them to exim which then delivers them to a Maildir style directory. that
works great.

the problem is sending mail out through exim4 to my isp. my isp only
supports LOGIN auth. i have exim4 setup with the "smarthost" option. i
used the address of the smtp server of my isp as the smarthost. i edited
smtp_remote in the conf.d directory and i put my information in the
passwd.clients file. i also have my user name aliased to my isp email
address in the file /etc/email-addresses

the problem is i keep getting a "550 5.1.8 you are not allowed to send
mail". i know that i am because i can send mail through evolution
directly to the isp, but i want all my mail to go through exim4.

i believe that the problem is exim4 is not sending the authentication
information. how can i test this? can anyone see a set that i have
missed? any help would be appreciated.

thanks