I am having server which hosts 70-80 websites and also using relay server for smtp using postfix using mysql database for domain and email boxes.
I have also activated the phpmail.log for sendmail.
I am getting notification from them that we have received a mail from new sender, which needs to be validated.
What I find is that the sender is not on my domain list.
Now while checking the mail.log or phpmail.log there is no trace of the senderid.
What other steps I can take to dectect the source of this mail from where this script is run?