[Dovecot] Namespace help

[Joy]

Dear All,
              I am currently using courier-imap which uses INBOX.
namespace configuration now i am willing to use dovecot instead of
courier-imap but without INBOX. namespace configuration means default
namespace of dovecot which helps me to sort out no of mail client
issues as well.

I know that i can change the default namespace configuation of dovecot
to work with courier-imap namespace but not willing to do that so
suggest me something which can help me doing the same.

Is it possible using postlogin script or something else ?

Thanks Regards

  Piyush Joshi