Having trouble with PHP and sendmail on your OSX install? Here's a little help from macos-x-server list:
In the /etc/mail/sendmail.cf file, add the line
O DontBlameSendmail=GroupWritableDirPathSaferight after the line
#O DontBlameSendmail=safeand this should allow PHP to send mail out through sendmail.
Mac OS X Hints
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