Marco.k

Thanks for thinking allong. Ill try and contact the server admins, and ofcours contact the users that are sending the spam ( asking them to clean the infected computers). Greatings. Marco Edit: ps Indeed their server and rules .. but they do complain about spam, so gues they want it to stop

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

1. I know and agree on this. 2. Why do they accept mail from outside the internal network at a other port then 25? 3. I know of one and will find more mail servers that accept mail from internet at port 587 ( dont know why .. and they ask me for a header if i ask why) 4. Is it not a good idea to let only your own MTA's deliver mail to that part of the platform ? 5. I cant understand why any ISP has a smtp server accepting mail from the internet at a other port then 25.

I was wondering: Why do some ISP's allow inbound smtp trafic to ports like 587. I dont understand why a smtp server want to get it's mail deliverd on a other port than 25. (you cant say in a mx record you want your mail deliver at port x .. so) Normal other MTA's dont deliver mail on it and clients shut be or from there network or authenticated. Are there many more of these port where some mailservers accept mail to there domain ? Greatings, Marco.