On Sun, 9 Jan 2005 14:51:31 -0500 (EST), Sean Donelan <sean@donelan.com> wrote:
On Sun, 9 Jan 2005, Suresh Ramasubramanian wrote:
So, a quick poll .. how many ISPs here have noticed this behavior, and applied bidirectional filters? And if they've applied port 25 filters bidirectionally, have they noticed any problems with this setup?
Have you looked at the following :-)
http://www.outblaze.com/main.php?id=antispam&page=anti_infoadmin
I wrote some part of that doc (though the part about filtering you quoted seems to have been written by a colleague) - you'll find docs all over the 'net, that have a lot more detail. Finding out how many ISPs are doing this is a rather different thing from finding out how many docs out there are recommending it. Especially as I'm seeing a marked uptick in this sort of behavior, from ISPs that I thought normally do filter port 25. As John points out earlier there were cases of specific people doing this, though now I think we're seeing trojans do it - a rather more dangerous development. --srs -- Suresh Ramasubramanian (ops.lists@gmail.com)