[Exim] Sending mail

This is a multi-part message in MIME format.
--
[ Picked text/plain from multipart/alternative ]
Hi!

i'm a new exim/sendmail user and i've just configured a little server for
delivering mail with exim. My problem is that there is a process launched by
another application (nagios) that periodically sends notifications to a
mailbox specified in nagios config (user ithelpdesk@...net) but it only
sends to root recipient. Where i can specify recipients to send from my
application?

Anther one: How i can specify From: line on my notifications via exim?

Thanks in advance and sorry if this question is so newbie o:)
--