When I use this:

mail_location = maildir:/home/mail/%d/%n

the dovecot-uidlist file is located in:

/home/mail/example.com/user/dovecot-uidlist

But when I change it to:

mail_location = maildir:/home/mail/%d/%n:CONTROL=/var/mail/%d/%n

then it's stored in:

/var/mail/example.com/user/.INBOX/dovecot-uidlist

Any idea why is not stored in: /var/mail/example.com/user/dovecot-uidlist ?