NIS domain name not set - NIS lookups disabled

NIS domain name not set - NIS lookups disabled

#postconf | grep nis

output:
alias_maps = hash:/etc/aliases nis:mail.aliases
or
alias_maps = hash:/etc/mail/aliases nis:mail.aliases


disable NIS lookups (as root):
# postconf -e alias_maps=hash:/etc/aliases
or
# postconf -e alias_maps=hash:/etc/mail/aliases