[Dovecot] Problem with IMAP and MAIL environment

[Luis Miguel Cruz]

Here is the problem:	

Jul 19 10:40:17 mail1 pop3(master): mbox: Can't create root IMAP folder 
/home/usuarios/master/mail: Permission denied
Jul 19 10:40:17 mail1 pop3(master): MAIL environment missing and 
autodetection failed (home /home/usuarios/master)
Jul 19 10:40:17 mail1 dovecot: child 3528 (pop3) returned error 89

Is there anyway to avoid it?
Thanks.