----- Original Message -----
From: "Markus Stumpf" <maex-lists-spam-ietf-asrg(_at_)Space(_dot_)Net>
To: "Alan DeKok" <aland(_at_)ox(_dot_)org>
Cc: <asrg(_at_)ietf(_dot_)org>
Sent: Friday, December 12, 2003 11:43 PM
Subject: Re: [Asrg] 6. Proposals: MTA MARK vs port 25 filtering?
Hoi Alan,
[cut]
On Fri, Dec 12, 2003 at 10:58:21AM -0500, Alan DeKok wrote:
There is no way for any mailserver administrator or ISP or router admin
to decide whether a customers mail is "good" or "bad" unless he can read
the email. Reading and controlling each and every email before letting
it pass the border of your IT infrastructure is impossible for anyone/
any business with more than 100 emails a day and 5 people. Even more if
you have to take care about data protection.
So it is useless to block port 25 for everyone "just because".
We have an AUP that forbids to send "bad" mails (whatever that means, in
our case it's including UCE and spam) and we can take actions if a
customer
fails to adhere. But unless he fails, he has free and unfiltered access to
the Internet and IMHO this is a good thing.
This is exactly why MTAMark or ReverseMX should be in use.
Customers can take unrestricted connections to anywhere. It's
just that they have to use MTA of the ISP for sending smtp messages
or ask the ISP to register customers own MTA to the reverse dns.
It's up to the receiving MTA to utilize that information.
Besides, blocking some defined port propably works as long as
SRV record is not widely utilized.
(http://www.menandmice.com/online_docs_and_faq/glossary/glossarytoc.htm?srv.
record.htm)
Tomi
_______________________________________________
Asrg mailing list
Asrg(_at_)ietf(_dot_)org
https://www1.ietf.org/mailman/listinfo/asrg