Help!!
My ISP has fired me a mail with regards to potential spam that they
believe is eminating from my server. Having had a look, i seem to be
getting nothign out of the ordinary, however one thing that was went in
the mail seemed to make sense...
"Your server may be being used for a reverse NDR (None Delivery Report)
attack without your knowledge. We recommend that your server is set to
reject e-mails on attempted delivery, rather than accepting the email
and then producing the NDR".
Does anyone know a way of doing this?? I am currently running
mailscanner and spam assassin.
Also, whats the best free Open relay checker out there nowadays?
How can i locate the source of the spam - can i grep the maillog to find
it? It was onlt sent this morning!
Anything anyone else can advise??
Thanks
Paul