Create Mailbox

[Allama Hicham]

Hi everyone,
I'm working With Unix and Solaris and I'm insttaling Qmail.
When I send a mail to a local user and I open the /var/log/syslog, I
find that message
 "delivery26.: failure :Sorry,_no_mailbox_here_by_that_name._(#5.1.1)/"
So I must create a Mailbox!
But I don't now how can i do that!
Thank you for Anser!