[20975] in North American Network Operators' Group
Re: Despamming wholesale dialup
daemon@ATHENA.MIT.EDU (Lyndon Nerenberg)
Fri Oct 30 14:51:34 1998
Date: Fri, 30 Oct 1998 12:09:13 -0700
From: Lyndon Nerenberg <lyndon@esys.ca>
To: phil@whistler.intur.net
cc: nanog@merit.edu
In-Reply-To: <199810301838.MAA05627@whistler.intur.net>
On 30 Oct, Phil Howard wrote:
> Bryan Bradsby wrote:
>
>> Block port 25 (only) from all "open modem banks" (TM) to my SMTP servers.
> The question is whether a dialup user should use the SMTP server of the
> facility provider, or of the ISP that actually resells the account.
> I think the SMTP server that should be used when dialing that national
> provider is the SMTP server provided by that national provider, unless
> some kind of VPN is used (to be more technically correct, use the SMTP
> server of the provider of IP addressing).
Port 25 restrictions don't solve the problem. The real solution is for
everyone to start leaning on their server vendors to deliver
authenticated SMTP. If you restrict relaying to only work with
authenticated connections, the problem goes away for the most part.
This solves another problem: mobile users. E.g., if I'm on the road
doing corporate mail, I want to connect to my corporate mail server
running encrypted SMTP. I certainly don't want my mail sitting on some
random ISPs mail hub.
I don't expect this to catch on in the client space in any major way
until the issue is forced by the servers denying relay services to
unauthenticated clients.
--lyndon
