<https://kb2.masterweb.com/tpesan-kesalahansendmailcant-send-mailsender-domain-not-belong-user.html>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://kb2.masterweb.com/tpesan-kesalahansendmailcant-send-mailsender-domain-not-belong-user.html>