I have "localhost" as you suggested.
The odd thing is my /var/log/mail.log says Postfix delivered the email fine...
Sep 9 18:44:11 webwork postfix/smtpd[4133]: connect from localhost[127.0.0.1]
Sep 9 18:44:11 webwork postfix/smtpd[4133]: 8E514A75E: client=localhost[127.0.0.1]
Sep 9 18:44:11 webwork postfix/cleanup[4137]: 8E514A75E: message-id=<20140909_184411_014667.>
Sep 9 18:44:11 webwork postfix/qmgr[1174]: 8E514A75E: from=<>, size=1295, nrcpt=1 (queue active)
Sep 9 18:44:11 webwork postfix/smtpd[4133]: disconnect from localhost[127.0.0.1]
Sep 9 18:44:11 webwork postfix/local[4138]: 8E514A75E: to=<cs@philfour.com>, relay=local, delay=0.06, delays=0.05/0.01/0/0, dsn=2.0.0, status=sent (delivered to mailbox)
Sep 9 18:44:11 webwork postfix/qmgr[1174]: 8E514A75E: removed