SMTP rate-limits [Was: Re: ingress SMTP]

[fergdawg at netzero.net (Paul Ferguson)]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

- -- Simon Waters <simonw at zynet.net> wrote:

>If the ISP blocks port 25, then the ISP is taking responsibility for 
delivering all email sent by a user, and they have to start applying rate 
limits. Otherwise if they send all email from their users, all they've done
is take the spam, and mix it in with the legitimate email, making spam 
filtering harder.
>

Okay, I can understand why an ISP might want to apply SMTP
rate-limits, but to clarify, I'm assuming you meant that ISPs
(if they do block tcp/25 outbound to anything other than their
own MTAs) need to watch for excessive SMTP utilization, which might
indicate a spammer-client (?).

...as opposed to arbitrary SMTP rate-limits.

Yes?

- - ferg

-----BEGIN PGP SIGNATURE-----
Version: PGP Desktop 9.6.3 (Build 3017)

wj8DBQFIwO90q1pz9mNUZTMRAneaAJwMgmIz99bPUYJ2HgUD6Zs1MOFXgQCgmsPY
eUtV2bBKymWfxNwNOgWfp5w=
=bdk+
-----END PGP SIGNATURE-----


--
"Fergie", a.k.a. Paul Ferguson
 Engineering Architecture for the Internet
 fergdawg(at)netzero.net
 ferg's tech blog: http://fergdawg.blogspot.com/