My new dedicated was just set up tonight.. I am a busy beaver installing and setting up what I can..

Just installed chkrootkit and set it to email the reports.. but they didnt go out.. the bounce notice shows:
... while talking to mx2.optonline.net.:
>>> MAIL From:<root@stag.spry.com> SIZE=565
<<< 550 5.1.8 invalid/host-not-in-DNS return address not allowed
554 5.0.0 Service unavailable

is that because the server is not fully set up yet??