[otrs] exim configuration

Dear All, As i have read the docs of otrs, it is clearly mentioned how we can configure the otrs mail system with exim and fetchmail. My requirement is for outgoing mail use exim and for incoming mail use fetchmail.How can i setup/configure the same with otrs by frontend and backend ? I have exim running on the same machine. -- Shrinivas Devarkonda, Email : d.shri@drushti.in.