Ok ill explain why i asked it.
The ISP where i work recently blocked all outging trafic to port 25 from our customers.
The amount of spam being send from our network has dropped massively.
Only we are still are getting some complains.
Afther checking the headers it looked like they where still being deliverd directly to the complaining party.
Afther some checking and testing some of the complainers where accepting mail to there domain at a other port then port 25.
So it looks like there are some spam bots that go around the block that way.
I was hoping one of you have seen this before or know why this is ( is it a bad configuration of the complaining party?)
Greatings,
Marco
2. see 3
3. The customers/ users on the road seem to only need authentication when sending away from the isp.
So the mail server accepts mail to it's domain(s) at other ports then port 25.
Is it me or is this a misconfiguration ?
ps Not giving the servers becouse i dont want them to get more spam.
Greatings,
Marco