[Exim] Problem with from header

Hi

I am using exim-3.35 with evolution as my mailer and a wierd problem has
arisen

The email address on outgoing mail is being written as
mike@<host>.localdomain in the recieved from header

instead of mike@<my mail domain>

in /etc/exim.conf I have
qualify_domain = <my mail domain>

however this does not seem to be working

my from address is correct on mail, but because the recieved header is
pointing to localhost, delivery fails when the other end does an mx
lookup

Anyone ny ideas about this