There is an annoying problem with RT3 sending emails through exim are shown in outlook as being from apache@your-domain.com, istead of the email assigned to the queue in RT (like support@your-domain.com).
To fix this boolshit:
– add a line trusted_users: apache into exim config (you might need to replace apache with whatever user apache is running under)
– add a line apache@your-domain.com \”${if !eq {$header_From:}{}{$header_sender:$header_From:}fail}\” Fs in the rewrite section of exim config (adjust apache@your-domain.com to whatever fits you)
– restart/reload exim