Hello (not helo :-) I am working on a spam filter and so I find myself spending a lot more quality time with mail logs than I used to. One of the things I have noticed is that I will get a lot of connections that send a HELO command and then disconnect. Sometimes I get this repeated several times a minute from the same IP for hours on end. What is going on here? Should I block these IPs? Am I being scanned? By what? To what end?
Thanks, rg
