[Dovecot] What owner/permissions for virtual homes?

VirtualUsers.Home.txt:

The directory layouts for home and mail directories could look like one of these (in the preferred order):

1. Mail directory under home, for example: home='/var/vmail/domain/user/' mail='/var/vmail/domain/user/mail/'

Who should be the owner of these directories, with that permissions?

Does it make a difference if it's /home/vmail rather than /var/vmail?

Thanks, Jay