[imp] Invalid mailbox name while sending new message

[Dan Brown]

Quoting Liutauras Adomaitis <liutauras at infosaitas.lt>:

>     'folders' => 'INBOX.',
>     'namespace' => '',

It's been a while since I used Courier, but I'm 99% sure that those  
parameters were reversed for me:

     'folders' => '',
     'namespace' => 'INBOX.',