[exim] "authenticator yielded 13" and SMTP AUTH help

Hi,

I am having a problem with SMTP authentication. My ISP now requires
authentication when transporting mail from local to remote SMTP
server. I have read the man pages, searched Debian and Exim mail
list archives, and read the READMEs, but I still can't get it
to work.

Here is the output when telneting to port 25 of the server:
*******************************************
> telnet smtp.pacbell.yahoo.com 25
Trying 68.142.198.11...
Connected to smtp.sbc.mail.yahoo4.akadns.net.
Escape character is '^]'.
220 smtp103.sbc.mail.mud.yahoo.com ESMTP
EHLO kimagure
250-smtp103.sbc.mail.mud.yahoo.com
250-AUTH LOGIN PLAIN XYMCOOKIE
250-PIPELINING
250 8BITMIME
*******************************************

Next, I tried to send an email through exim

*******************************************
kimagure:/etc/exim4# exim4 -v -d+auth xxxxx@???
Exim version 4.52 uid=0 gid=0 pid=30679 D=fbb95cfd
Berkeley DB: Sleepycat Software: Berkeley DB 4.2.52: (December 3, 2003)
.
.
.
SMTP<< 220 smtp112.sbc.mail.mud.yahoo.com ESMTP
68.142.198.11 in hosts_avoid_esmtp? no (option unset)
SMTP>> EHLO kimagure

waiting for data on socket
read response data: size=98
  SMTP<< 250-smtp112.sbc.mail.mud.yahoo.com
         250-AUTH LOGIN PLAIN XYMCOOKIE
         250-PIPELINING
         250 8BITMIME
68.142.198.11 in hosts_require_tls? no (option unset)
using PIPELINING
68.142.198.11 in hosts_require_auth? no (option unset)
gethostbyname2(af=inet6) returned 3 (NO_RECOVERY)
gethostbyname2 looked up these IP addresses:
  name=smtp.sbc.mail.yahoo4.akadns.net address=68.142.198.11
68.142.198.11 in hosts_try_auth? yes (matched "smtp.pacbell.yahoo.com")
scanning authentication mechanisms
plain authenticator yielded 13
login authenticator yielded 13

SMTP>> MAIL FROM:<xxxxx@???>
SMTP>> RCPT TO:<xxxxxxx@???>
SMTP>> DATA
waiting for data on socket
read response data: size=105
SMTP<< 530 authentication required - for help go to http://help.yahoo.com/help/us/sbc/dsl/mail/pop/pop-11.html
waiting for data on socket
ok=0 send_quit=1 send_rset=1 continue_more=0 yield=0 first_address is not NULL
SMTP>> QUIT
******************************************

I tried googling and searching exim mail list archives for
"authenticator yielded 13" as I'm guessing it is an error
message. However, I do not know what it stands for.

I have a /etc/passwd.client file that required for authentication.
I have tried to follow the instructions, but there seems to be
some conflict with the exact syntax. Within exim4.conf it says the
password should be "crypted". In the Debian readme on authentication
that came in the package, it just says "password". The RFC says
the actual data being passed is MIME/base64. Currently, I have my
password as plain text.

So to help get me started on trying to fix my email, what
does "authenticator yielded 13" mean? I am guessing something
failed. Also, what syntax should be in the /etc/passwd.client file?

Thanks,

Anthony