[Exim] Spool directory ownership

Hi all

I've managed to get exim installed and issuing exim -bV works :-)
So does exim -v -bt <local username> :-))
Even exim -v -bt <local username> and exim -v -bt <remote address> works :-)))

But...*sigh*...I have noticed that the spool directory is owned by root so when
I attempt to deliver a mail directly to Exim, it complains that it cannot open
the /var/log/exim_mainlog which I understand because it's running as user
exim...

What have I done wrong? Can I change ownership of the spool directory from root
to exim?

TIA
/wiZZ