On Sun, 9 Jan 2005, Suresh Ramasubramanian wrote:
.. and if it has been tried, have you noticed any issues with this?
Please consider the situation of net abuse with the source address being an infected PCs on a dialup pool that has port 25 filtering enabled.
...description of 'fantasy mail' removed...
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?
I believe reseller contracts have included this for over 2 years now, John StClair's efforts to get these in place are the primary reason they exist for our customers.
This ISP's post is only the second I've seen noting such behavior in a few months, the first being a nanog post in Aug 2004 by Hank Nussbacher - http://www.cctec.com/maillists/nanog/current/msg03171.html
We'd first seen this behaviour over 2 years ago... quite a bit actually over that time as the filters had been put into place. -Chris