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Jonas,

thanks for the reply. Some queries below, if you have the time.

Mike

On 6/14/07, Jonas Eckerman wrote:
>
> Blocking because a system/netblock has made many attempts to send
> to non-existant users makes sense.
>
> Any single address from wich a certain number of such attempts is
> done during a the last n minutes are blocked with a tenporary
> failure here. Netzero might well be doing something similar.



Granted, but it seems to me that it is very much easier to detect these
violations at the destination that at the source. The implication is that w=
e
must keep count of every failed recipient for every sender on our domain an=
d
maintain a rolling average. Unless there is some tool or some feature of my
current tools that I am unaware, I am not sure that this is feasible.
Perhaps there is some industry accepted means of doing this offline?

Whatever the technology, if these ISPs are genuinely interested in blocking
spam, wouldn't it make sense for them to provide some more detailed
information on who the offender was (email address) so that we would have a
starting point. Many other sites provide us with this evidence and we
quickly investigate and either block the sender or correct their behavior.

Of course it is also possible that they block in a way that
> doesn't make sense.
>
> Without knowing what your system(s)/netblock did to their
> system(s), what made them block you, and how long the temporary
> period is, it's impossible to judge wether it makes any sense or not.
>
> Regards
> /Jonas
>
> --
> Jonas Eckerman, FSDB & Frukttr=E4det
> http://whatever.frukt.org/
> http://www.fsdb.org/
> http://www.frukt.org/
>
>


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Jonas,

thanks for the reply. Some queries below, if you have the tim=
e.

Mike

On 6/14/07, =3D"gmail_sendername">Jonas Eckerman < frukt.org">
jonas_lists@frukt.org> wrote:
" style=3D"border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0=
..8ex; padding-left: 1ex;">Blocking because a system/netblock has made many =
attempts to send

to non-existant users makes sense.

Any single address from wich =
a certain number of such attempts is
done during a the last n minutes ar=
e blocked with a tenporary
failure here. Netzero might well be doing som=
ething similar.

Granted, but  it seems to me that it is very muc=
h easier to detect these violations at the destination that at the source. =
The implication is that we must keep count of every failed recipient for ev=
ery sender on our domain and maintain a rolling average. Unless there is so=
me tool or some feature of my current tools that I am unaware, I am not sur=
e that this is feasible. Perhaps there is some industry accepted means of d=
oing this offline?=20


Whatever the technology, if these ISPs are genuinely interested in =
blocking spam, wouldn't it make sense for them to provide some more det=
ailed information on who the offender was (email address) so that we would =
have a starting point. Many other sites provide us with this evidence and w=
e quickly investigate and either block the sender or correct their behavior=
..


olid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Of =
course it is also possible that they block in a way that
doesn't mak=
e sense.


Without knowing what your system(s)/netblock did to their
system=
(s), what made them block you, and how long the temporary
period is, it&=
#39;s impossible to judge wether it makes any sense or not.

Regards

/Jonas

--
Jonas Eckerman, FSDB & Frukttr=E4det
=3D"http://whatever.frukt.org/">http://whatever.frukt.org/
=3D"http://www.fsdb.org/">http://www.fsdb.org/
..frukt.org/">
http://www.frukt.org/





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