(CentOS 6.4, ISPConfig3, GNOME, NGINX, 64 bit, 4 Quad Cores) Hello, I am hosting one site on my server and have received 2 emails to "."@localhost from China... I have searched the net for information on this issue and have found information on "how" to do this, but now why I am receiving it?? Any insight on this issue would be appreciated. Is this an exploit or a blanket send to all open localhost mail servers? Thanks!