Postfix: Setup DNS spf
From OnnoCenterWiki
Caranya:
Name/Host/Alias: Enter @ or leave it blank. Your other DNS records might indicate which entry is correct. Time to Live (TTL): Enter 3600 or leave the default. Value/Answer/Destination: Enter v=spf1 include:_spf.google.com ~all
Misalnya:
onnocenter.or.id. IN TXT "v=spf1 include:_spf.google.com ~all"