dovecot error ..

doveconf: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:85: add auth_ prefix to all settings inside auth {} and remove the auth {} section completely
doveconf: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:87: passdb pam {} has been replaced by passdb { driver=pam }
doveconf: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:89: userdb passwd {} has been replaced by userdb { driver=passwd }