[exim] gmail with exim

Hello users

I'm new to exim. I'm trying to do something I can find in the docs or from
this list

Our company uses Gmail and Google Apps for our email servers.We have our
domain email routed through gmail. We have an application that runs as a
user. When it tries to sendmail with the -f flag the MTA should use the from
address to send email as that user

sendmail -f bob@???

with the -f flag bob@??? should relay mail through
smtp.gmail.com:587 using bob@??? gmail username

I've found similar config for a single user relay. But how do I relay
through gmail with multiple gmail accounts

examples would be helpful

Ubuntu 6.10
exim4 4.62

Regards
--
J. Scott Andreas
email: scott@???