Folks, if you are using QMAIL, try this and don't use "qmail-inject -f"
Systems not using sendmail should set this directive to the sendmail wrapper/replacement their mail system offers, if any. For example, Qmail users can normally set it to /var/qmail/bin/sendmail.
Like:
sendmail_path = "/var/qmail/bin/sendmail -t -i"
Woozy