Hi all
On Friday 13 April 2007, Schmid wrote:
Funny thing is one ISP is switching off his SMTP relay telling the client to use other smtp relay in the wild and call that a first action according to the "stop spam" campaign. another one is blocking port25 und force the user to use the ISP?s SMTP Relay and even explain this is done due to the "stop spam" campaign
Here's what I think would be reasonable to fight spam. And in the first place it really would help fight spam comming from trojanized computers - until spammers start to use the Outlook| Thunderbird|whatever configured authenticated SMTP/Submission Access:
* Block destination port 25. This prevents bots from sending email directly to the victims MXes. No one wants to (must not) run an MTA in a dialup range: Many MXes dont accept emails orginating from dial-up rages. No one wants to (must not) run an MX in a dial-up range. The risk of delaying or losing email due to a IP change is not acceptable. And what if the successor of the IP runs an MX which accepts all Mail..?
* Provide an relaying MTA accepting emails from authenticated connections on port 25 or 587 (Submission, which is intended for exactly this use case). I dont know if Tele2/Econophone do this.
* Allow connections with destination port 587 to let your users relay to any thrid party email provider. Tele2/Econophone do this.
Given the second point is OK, this whole blocking thing this not a bad idea. And its not that hard to configure fetchmail/authenticated relaying to a smarthost for geeks who want to run their own email infrastructure (in contrary it adds som salt to the whole soup ;)
Now waht I think is really bad is the thing that Econophone/Tele2's Information website is really bad. These three very easy points are no where clearly explained. The lengthy FAQ beats arround the bush and rather confuses the reader than making the situation clear to him. *hinthinthint*
Probably one of these guys can confirm this or explain the differences (and probably add it to their Information Pages...).
Have fun
Michi