[Evolution] Error on local mail

[Cory Bannister <bannister_cory hotmail com>]

I have set up evolution to use standard unix mailbox file and the path is
/var/mail/username
When I go to my inbox and hit send and receive I receive 
"Error while performing operation
Coud not creat lock file for /var/mail/username: Permission denied"

I'm currently using Balsa to view my local mail.  Am I doing this wrong in
Evolution or is this not supported yet?
I'm using Evoltion 0.10

Thanks,
Cory