[Dovecot] question mailbox format

[sc2 at gmx.at]

ok after playing a while now it works , but i have one problem open..
a.) now he makes for pop3 index files in /var/indexes/%u/imap/index etc...
you said that is correct too if i only use pop3 ?

b.) i have as INBOX file /var/spool/mail/%u set, when somebody logs in, and 
the mailbox exist he gets the email (from mbox file), but when the mbox does 
not exist he makes a directory, instead of a file like /var/spool/mail/%u.
The problem is when a new mail comes and the mbox file does not exist, the 
mail is saved to the directory as msg and not as mbox file
any ideas?
Btw im using version 1.0.0
thx