Fwd: Unable to setup SMART Host in local mail server

[samuel dinakar sama]

HI all,

I have setup ed a Mail server and i wanna use a  hosting Mail server SMTP
(My Mail server service provider) .

Configuration in sendmail.cf file every thing seems to be fine. Though i
have mentioned in the configuration file SMART host my external mail server
IP address it is failing to pick up the mentioned address.

# dnl define ('SMART_HOST', ' mail.X.com <http://mail.x.com/>')dnl

the following i have given in /etc/mail/authinfo file

AuthInfo:<mail.x.com> "U:samuel at x.com" "P:<xxxxxxx>" "M:DIGEST-MD5"


For authentication I tried giving my mail ID user name  and password but it
is not accepting it says *User unknown.*
i received this in postmaster mail. It calling my internet ISP IP rather to
call my hosting mail server ISP IP

*I do not understand what authentication is needed  for my local mail server
to connect  to my external mail server ?

*please help in this regard i am unable to proceed  further.

Many thanks in Advance.

Regards,
*Sam*