I have a Virtualmin installation on an Ubuntu server. I just checked the /var/log/syslog and it seems that it is spewing spam at an alarming rate.
I don't have much experience on Virtualmin on Ubuntu but on the systems that I have experience with if I saw this I would check to see if the SMTP server required authentication or not and if it did not I would set it to require authentication. Can someone tell me how to do this and what else I might want to look at?
Thanks in advance, Chris