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After RFC 821 was mutilated by RFC 1123 email could be forged.
Forwarding was broken by RFC 1123 5.3.6(a) about 19 years ago. The
spammers figured it out about seven years ago. The concept of
"forwarding" as it was known before RFC 1123 5.3.6(a) does not work any
more, "forwarding" is now a part of the problem, like open relays.

Because people want to forward email and the ability to track them was
removed. People now can and do forge email. It has become a major
problem just like open relays. Something has to change. SPF put back a
way to tell if an email was forged.

--
Boyd Gerber <gerberb@zenez.com>
ZENEZ 1042 East Fort Union #135, Midvale Utah 84047

On 5 Mar, 22:56, Boyd Lynn Gerber <gerb...@zenez.com> wrote:
> After RFC 821 was mutilated by RFC 1123 email could be forged.
> Forwarding was broken by RFC 1123 5.3.6(a) about 19 years ago. *The
> spammers figured it out about seven years ago. *The concept of
> "forwarding" as it was known before RFC 1123 5.3.6(a) does not work any
> more, "forwarding" is now a part of the problem, like open relays.
>
> Because people want to forward email and the ability to track them was
> removed. *People now can and do forge email. *It has become a major
> problem just like open relays. *Something has to change. *SPF put backa
> way to tell if an email was forged.

This is the wrong newsgroup for this topic, op on ove to the network
abuse discussion groups for this topic.

And there are some usable technologies to actually handle the
forwarding problem, which is that the "bounce" address for a message
does not get reset by the forwarding server to bounce back to the
forwarding server itself, which should then pass it back to the
message submitter. The result is that no one can easily tell the
difference between a forwarded message and a faked one with a
different "bounce" address, inundating the rest of us with the bounced
spam.

There are technologies to store a registry of incoming email, encode
the "bounce" address going out, and allow the forwarding server to
decode the bounce message and get it back to the recipient. It's not
well integrated yet with major SMTP servers.

Nico Kadel-Garcia wrote:
> On 5 Mar, 22:56, Boyd Lynn Gerber <gerb...@zenez.com> wrote:
>> After RFC 821 was mutilated by RFC 1123 email could be forged.
>> Forwarding was broken by RFC 1123 5.3.6(a) about 19 years ago. The
>> spammers figured it out about seven years ago. The concept of
>> "forwarding" as it was known before RFC 1123 5.3.6(a) does not work any
>> more, "forwarding" is now a part of the problem, like open relays.
>>
>> Because people want to forward email and the ability to track them was
>> removed. People now can and do forge email. It has become a major
>> problem just like open relays. Something has to change. SPF put back a
>> way to tell if an email was forged.
>
> This is the wrong newsgroup for this topic, op on ove to the network
> abuse discussion groups for this topic.

I take offense at your chastising Boyd for this post. I believe that it
was in response to my original post looking for help in resolving the
originating IP address's ISP and abuse@ values automatically in
the large number of bounced spam I have been receiving to my domain.

Boyd pointed out the use of SPF of which I have been ignorant and
I am looking at now as a means to remedy my problem. (Thanks again Boyd!).

I posted a problem, Boyd responded. Boyd posted the message you
responded to as additional information for clueless admin's (me)
as to why SPF is important.

>
> And there are some usable technologies to actually handle the
> forwarding problem, which is that the "bounce" address for a message
> does not get reset by the forwarding server to bounce back to the
> forwarding server itself, which should then pass it back to the
> message submitter. The result is that no one can easily tell the
> difference between a forwarded message and a faked one with a
> different "bounce" address, inundating the rest of us with the bounced
> spam.
>
> There are technologies to store a registry of incoming email, encode
> the "bounce" address going out, and allow the forwarding server to
> decode the bounce message and get it back to the recipient. It's not
> well integrated yet with major SMTP servers.
>
>
And your post is interesting as well. It could have stood alone without
the recommendation to move the discussion to another news group.

As an SCO admin, administering our own SCO servers and client's SCO servers,
my interest is in anything impacting our machines. I welcome Boyd's
contributions to this news group and look forward to reading anything
he takes the time to post as relevant to SCO users.

--
Steve Fabac
S.M. Fabac & Associates
816/765-1670

Steve M. Fabac, Jr. wrote:

> Nico Kadel-Garcia wrote:

>> On 5 Mar, 22:56, Boyd Lynn Gerber <gerb...@zenez.com> wrote:

>>> After RFC 821 was mutilated by RFC 1123 email could be forged.
>>> Forwarding was broken by RFC 1123 5.3.6(a) about 19 years ago.
>>
>> This is the wrong newsgroup for this topic, op on ove to the network
>> abuse discussion groups for this topic.
>
> I take offense at your chastising Boyd for this post. I believe that it
> was in response to my original post looking for help in resolving the
> originating IP address's ISP and abuse@ values automatically in
> the large number of bounced spam I have been receiving to my domain.


When replying to someone else's post, I try to do at least one of these
three things:

* Use 'reply' rather than 'new message' so that my posting contains an
NNTP "reference" header that points to the previous posting.

* Use the prefix "Re:" in the subject and preferably some clue that will
help folk locate the original thread.

* In the body of the message, make some mention, no matter how vague, of
the thread to which my message relates.

I expect that when I do none of the above, and discuss something
superficially unrelated to the newsgroup in which I post, some readers
may understandably be puzzled.

YMMV

Now that I maintain the threading this will be barried inside it. It
really should be a new post, but to satisfy you....

On Fri, 7 Mar 2008, RedGrittyBrick wrote:
> Steve M. Fabac, Jr. wrote:
> > Nico Kadel-Garcia wrote:
> > > On 5 Mar, 22:56, Boyd Lynn Gerber <gerb...@zenez.com> wrote:
> > > > After RFC 821 was mutilated by RFC 1123 email could be forged.
> > > > Forwarding was broken by RFC 1123 5.3.6(a) about 19 years ago.
> > >
> > > This is the wrong newsgroup for this topic, op on ove to the network
> > > abuse discussion groups for this topic.
> >
> > I take offense at your chastising Boyd for this post. I believe that it
> > was in response to my original post looking for help in resolving the
> > originating IP address's ISP and abuse@ values automatically in
> > the large number of bounced spam I have been receiving to my domain.

I was offended, but I considered the source. It was clear that a new
topic was needed, to clarify the discussion. It is not very valuable to
have to do a body search to get the information. Usenet really has
changed. We now see topic driffting and no change of subject. Many news
servers only keep things for 2 weeks. These marathon threads get articles
dropped and when you read they have not substance. I started a new thread
to clarify what was going on. The topic needed to be changed. It was
sparked from the discussion.

The problem is this now is driffting and has absolutly to do with the
thread. See below. Topic has nothing to do with the subject.

> When replying to someone else's post, I try to do at least one of these
> three things:
>
> * Use 'reply' rather than 'new message' so that my posting contains an
> NNTP "reference" header that points to the previous posting.

But with threading and the topic is no longer applicable. It gets barried
inside of a thread with no reference to the subject. A new thread should
start so that the discussion is about the subject.

> * Use the prefix "Re:" in the subject and preferably some clue that will
> help folk locate the original thread.

Yes as long as the discussion is about the orignal thread.

> * In the body of the message, make some mention, no matter how vague, of
> the thread to which my message relates.

That is often a good practice, but when time is short we do not always
follow good practice.

> I expect that when I do none of the above, and discuss something
> superficially unrelated to the newsgroup in which I post, some readers
> may understandably be puzzled.

But the tread had gone beyond the original subject. I started with a
clear subject that when referenced to the newsgroup... Assumtions.

1. This has something to do with SCO OS's or products. So therefore what
in the SCO OS needed to be explained.

(A) Sending email.

2. Assumption something in SCO that may be broken.

(A) SMTP.


So topic is choosen on SMTP being broken on SCO and that I should give
inforation on about how long. But being that what I am talking about is
also an issue with other OS, for this discussion it is not applicable. I
want to let people know that for SCO SMTP was broken about 19 years ago.
If I want to talk about abuse on a larger scale yes I would go to those
news groups, but given the SCO is the issue I do it here.

Given the source that started this drifft, has a bone to pick with SCO and
prefers to divert the subject. I will not go on more.


--
Boyd Gerber <gerberb@zenez.com>
ZENEZ 1042 East Fort Union #135, Midvale Utah 84047

On Fri, 7 Mar 2008, Steve M. Fabac, Jr. wrote:
> Nico Kadel-Garcia wrote:
> > On 5 Mar, 22:56, Boyd Lynn Gerber <gerb...@zenez.com> wrote:
> > > After RFC 821 was mutilated by RFC 1123 email could be forged.
> > > Forwarding was broken by RFC 1123 5.3.6(a) about 19 years ago. The
> > > spammers figured it out about seven years ago. The concept of
> > > "forwarding" as it was known before RFC 1123 5.3.6(a) does not work any
> > > more, "forwarding" is now a part of the problem, like open relays.
> > >
> > > Because people want to forward email and the ability to track them was
> > > removed. People now can and do forge email. It has become a major
> > > problem just like open relays. Something has to change. SPF put back a
> > > way to tell if an email was forged.
> >
> > This is the wrong newsgroup for this topic, op on ove to the network
> > abuse discussion groups for this topic.

No it is not. The discussion is about SCO's SMPT being broken. It just
happens that it applies to everyone. But the target is the SCO SMTP.

> I take offense at your chastising Boyd for this post. I believe that it
> was in response to my original post looking for help in resolving the
> originating IP address's ISP and abuse@ values automatically in
> the large number of bounced spam I have been receiving to my domain.
>
> Boyd pointed out the use of SPF of which I have been ignorant and
> I am looking at now as a means to remedy my problem. (Thanks again Boyd!).
>
> I posted a problem, Boyd responded. Boyd posted the message you
> responded to as additional information for clueless admin's (me)
> as to why SPF is important.

Thanks that was my intention. For SCO admins

> > And there are some usable technologies to actually handle the
> > forwarding problem, which is that the "bounce" address for a message
> > does not get reset by the forwarding server to bounce back to the
> > forwarding server itself, which should then pass it back to the
> > message submitter. The result is that no one can easily tell the
> > difference between a forwarded message and a faked one with a
> > different "bounce" address, inundating the rest of us with the bounced
> > spam.
> >
> > There are technologies to store a registry of incoming email, encode
> > the "bounce" address going out, and allow the forwarding server to
> > decode the bounce message and get it back to the recipient. It's not
> > well integrated yet with major SMTP servers.
> >
> >
> And your post is interesting as well. It could have stood alone without
> the recommendation to move the discussion to another news group.

Agreed. The information was needed. I lacked time to really go in depth
to the issue.

> As an SCO admin, administering our own SCO servers and client's SCO servers,
> my interest is in anything impacting our machines. I welcome Boyd's
> contributions to this news group and look forward to reading anything
> he takes the time to post as relevant to SCO users.

Thanks,

--
Boyd Gerber <gerberb@zenez.com>
ZENEZ 1042 East Fort Union #135, Midvale Utah 84047

Steve M. Fabac, Jr. wrote:
> Nico Kadel-Garcia wrote:
>> On 5 Mar, 22:56, Boyd Lynn Gerber <gerb...@zenez.com> wrote:
>>> After RFC 821 was mutilated by RFC 1123 email could be forged.
>>> Forwarding was broken by RFC 1123 5.3.6(a) about 19 years ago. The
>>> spammers figured it out about seven years ago. The concept of
>>> "forwarding" as it was known before RFC 1123 5.3.6(a) does not work any
>>> more, "forwarding" is now a part of the problem, like open relays.
>>>
>>> Because people want to forward email and the ability to track them was
>>> removed. People now can and do forge email. It has become a major
>>> problem just like open relays. Something has to change. SPF put back a
>>> way to tell if an email was forged.
>>
>> This is the wrong newsgroup for this topic, op on ove to the network
>> abuse discussion groups for this topic.
>
> I take offense at your chastising Boyd for this post. I believe that it
> was in response to my original post looking for help in resolving the
> originating IP address's ISP and abuse@ values automatically in
> the large number of bounced spam I have been receiving to my domain.

Sorry, I didn't mean to chastise him for this. It's just that I don't
reasonably expect an OS based newsgroup to have the experience and expertise
in this particular subject that the network abuse newsgroups do. It's a fairly
sophisticated topic, and one in which I've been involved since the original
Canter&Siegel Usenet spams, and over which my wife and I had our first date.

> Boyd pointed out the use of SPF of which I have been ignorant and
> I am looking at now as a means to remedy my problem. (Thanks again Boyd!).

And this is something the network abuse groups would have more expertise on.
For example, SPF doesn't work well with sites that "forward" email without the
use of SRS to rewrite the "FROM" headers for bouncing email. If folks consider
it worthwhile, I was involved with SPF integration efforts quite early on, and
would happily share that. I'm concerned that casual mention of it won't reveal
the craziness that Microsoft has been doing to it with their "embrace and
extend" policy and mislabeling their "SenderID" settings as SPF 1.

It's worth a longer discussion with a more experienced group. If folks think
it belongs here, cool, but it's not really an SCO specific issue.

>> And there are some usable technologies to actually handle the
>> forwarding problem, which is that the "bounce" address for a message
>> does not get reset by the forwarding server to bounce back to the
>> forwarding server itself, which should then pass it back to the
>> message submitter. The result is that no one can easily tell the
>> difference between a forwarded message and a faked one with a
>> different "bounce" address, inundating the rest of us with the bounced
>> spam.
>>
>> There are technologies to store a registry of incoming email, encode
>> the "bounce" address going out, and allow the forwarding server to
>> decode the bounce message and get it back to the recipient. It's not
>> well integrated yet with major SMTP servers.
>>
>>
> And your post is interesting as well. It could have stood alone without
> the recommendation to move the discussion to another news group.

Well, thank you. I used to be active in the SPF discussion groups, and was
hopping mad when its creator (Meng Wong) made his mistaken collaboration with
Microsoft to extend it to include DomainKeys: this actually poisoned the
attempts to get SPF supported added as an official standard at a meeting at
Marid, due to Microsoft's patent encumbrances involving SenderID. The result
is that Sendmail developers and Postfix developers refused to include it as a
default component of their software, so it remains as an add-on utility,
rather than built-in.

> As an SCO admin, administering our own SCO servers and client's SCO
> servers,
> my interest is in anything impacting our machines. I welcome Boyd's
> contributions to this news group and look forward to reading anything
> he takes the time to post as relevant to SCO users.

I'm actually startled if you're using SCO servers as your external mail
servers. Given the awkwardness of package updates and lag time of updating
open source components such as sendmail, unless you're building your own, it
would seem difficult to keep SCO servers up-to-date with such features. Or are
you suggesting you would run hand-installed versions of Sendmail or Postfix on
such servers?

On Sat, 8 Mar 2008, Nico Kadel-Garcia wrote:
> > I take offense at your chastising Boyd for this post. I believe that
> > it was in response to my original post looking for help in resolving
> > the originating IP address's ISP and abuse@ values automatically in
> > the large number of bounced spam I have been receiving to my domain.
>
> Sorry, I didn't mean to chastise him for this. It's just that I don't
> reasonably expect an OS based newsgroup to have the experience and
> expertise in this particular subject that the network abuse newsgroups
> do. It's a fairly sophisticated topic, and one in which I've been
> involved since the original Canter&Siegel Usenet spams, and over which
> my wife and I had our first date.
>
> > Boyd pointed out the use of SPF of which I have been ignorant and I am
> > looking at now as a means to remedy my problem. (Thanks again Boyd!).
>
> And this is something the network abuse groups would have more expertise
> on. For example, SPF doesn't work well with sites that "forward" email
> without the use of SRS to rewrite the "FROM" headers for bouncing email.
> If folks consider it worthwhile, I was involved with SPF integration
> efforts quite early on, and would happily share that. I'm concerned that
> casual mention of it won't reveal the craziness that Microsoft has been
> doing to it with their "embrace and extend" policy and mislabeling their
> "SenderID" settings as SPF 1.

This is a bit wrong. There really is no Forwarding problem that needs to
be solved. Remember the SPF only deals with RFC 821/2821. The old mail
forwarding can no longer be tolerated. It is the same as having an open
relay. Open Relays are dead, or should be. The same with general
forwarding. Forwarding the old way is a form of an open relay. There is
not way to prevent forgery. SPF works on Mail From, sender ID works on
From. The difference between RFC 821/2821 and RFC 822/2822. SRS is just
one way to stop the forgery on forwarded mail. If the forwarder rewrites
the header to be from him then SRS is not needed. The email really his
from system, this system is acting as an open relay if it does not take
ownership of the Mail From. And as such has to change.

> It's worth a longer discussion with a more experienced group. If folks
> think it belongs here, cool, but it's not really an SCO specific issue.

Agreed.

> Well, thank you. I used to be active in the SPF discussion groups, and
> was hopping mad when its creator (Meng Wong) made his mistaken
> collaboration with Microsoft to extend it to include DomainKeys: this
> actually poisoned the attempts to get SPF supported added as an official
> standard at a meeting at Marid, due to Microsoft's patent encumbrances
> involving SenderID. The result is that Sendmail developers and Postfix
> developers refused to include it as a default component of their
> software, so it remains as an add-on utility, rather than built-in.

So your were also part of MADRID. About 6-8 months after MADRID was
closed, Meng worked with MS to give SenderID a backing of him. I too did
not like it. But SenderID is not DomainKeys! They are two different
methods of protecting the RFC 822/2822 From. MS has nothing to do with
Domain Keys.

> > As an SCO admin, administering our own SCO servers and client's SCO
> > servers, my interest is in anything impacting our machines. I welcome
> > Boyd's contributions to this news group and look forward to reading
> > anything he takes the time to post as relevant to SCO users.
>
> I'm actually startled if you're using SCO servers as your external mail
> servers. Given the awkwardness of package updates and lag time of
> updating open source components such as sendmail, unless you're building
> your own, it would seem difficult to keep SCO servers up-to-date with
> such features. Or are you suggesting you would run hand-installed
> versions of Sendmail or Postfix on such servers?

I do for the reasons given above. I prefer the milter concept. Keeps
thins modular.


--
Boyd Gerber <gerberb@zenez.com>
ZENEZ 1042 East Fort Union #135, Midvale Utah 84047

Nico Kadel-Garcia wrote:
> Steve M. Fabac, Jr. wrote:
>> Nico Kadel-Garcia wrote:
>>> On 5 Mar, 22:56, Boyd Lynn Gerber <gerb...@zenez.com> wrote:
>>>> After RFC 821 was mutilated by RFC 1123 email could be forged.
>>>> Forwarding was broken by RFC 1123 5.3.6(a) about 19 years ago. The
>>>> spammers figured it out about seven years ago. The concept of
>>>> "forwarding" as it was known before RFC 1123 5.3.6(a) does not work any
>>>> more, "forwarding" is now a part of the problem, like open relays.
>>>>
>>>> Because people want to forward email and the ability to track them was
>>>> removed. People now can and do forge email. It has become a major
>>>> problem just like open relays. Something has to change. SPF put
>>>> back a
>>>> way to tell if an email was forged.
>>>
>>> This is the wrong newsgroup for this topic, op on ove to the network
>>> abuse discussion groups for this topic.
>>
>> I take offense at your chastising Boyd for this post. I believe that it
>> was in response to my original post looking for help in resolving the
>> originating IP address's ISP and abuse@ values automatically in
>> the large number of bounced spam I have been receiving to my domain.
>
> Sorry, I didn't mean to chastise him for this. It's just that I don't
> reasonably expect an OS based newsgroup to have the experience and
> expertise in this particular subject that the network abuse newsgroups
> do. It's a fairly sophisticated topic, and one in which I've been
> involved since the original Canter&Siegel Usenet spams, and over which
> my wife and I had our first date.

I respect your experience and effort you have put into this subject.
I am not trying to solve the world's spam problem. Just trying to
protect my domain from being blacklisted due to the abuse perpetrated
by others in faking the From: tag in their spam.

>
>> Boyd pointed out the use of SPF of which I have been ignorant and
>> I am looking at now as a means to remedy my problem. (Thanks again
>> Boyd!).
>
> And this is something the network abuse groups would have more expertise
> on. For example, SPF doesn't work well with sites that "forward" email
> without the use of SRS to rewrite the "FROM" headers for bouncing email.
> If folks consider it worthwhile, I was involved with SPF integration
> efforts quite early on, and would happily share that. I'm concerned that
> casual mention of it won't reveal the craziness that Microsoft has been
> doing to it with their "embrace and extend" policy and mislabeling their
> "SenderID" settings as SPF 1.
>
> It's worth a longer discussion with a more experienced group. If folks
> think it belongs here, cool, but it's not really an SCO specific issue.

Granted. But again, I'm not trying to solve the world's spam problem.
Just trying to contribute by automating reporting to the abuse@ e-mail
for the ISP's where the spam is originating to identify the source
IP and give them supporting documentation to build the case to terminate
willful offenders or contact unsuspecting (clueless) home users with
infected machines.

As I take the steps to implement SPF in the DNS MX record and A
record, we may see a falloff in bounced spam reaching my domain.
Until then, I will continue submitting abuse reports to the
responsible ISP's.

>
>>> And there are some usable technologies to actually handle the
>>> forwarding problem, which is that the "bounce" address for a message
>>> does not get reset by the forwarding server to bounce back to the
>>> forwarding server itself, which should then pass it back to the
>>> message submitter. The result is that no one can easily tell the
>>> difference between a forwarded message and a faked one with a
>>> different "bounce" address, inundating the rest of us with the bounced
>>> spam.
>>>
>>> There are technologies to store a registry of incoming email, encode
>>> the "bounce" address going out, and allow the forwarding server to
>>> decode the bounce message and get it back to the recipient. It's not
>>> well integrated yet with major SMTP servers.
>>>
>>>
>> And your post is interesting as well. It could have stood alone without
>> the recommendation to move the discussion to another news group.
>
> Well, thank you. I used to be active in the SPF discussion groups, and
> was hopping mad when its creator (Meng Wong) made his mistaken
> collaboration with Microsoft to extend it to include DomainKeys: this
> actually poisoned the attempts to get SPF supported added as an official
> standard at a meeting at Marid, due to Microsoft's patent encumbrances
> involving SenderID. The result is that Sendmail developers and Postfix
> developers refused to include it as a default component of their
> software, so it remains as an add-on utility, rather than built-in.
>
>> As an SCO admin, administering our own SCO servers and client's SCO
>> servers,
>> my interest is in anything impacting our machines. I welcome Boyd's
>> contributions to this news group and look forward to reading anything
>> he takes the time to post as relevant to SCO users.
>
> I'm actually startled if you're using SCO servers as your external mail
> servers. Given the awkwardness of package updates and lag time of
> updating open source components such as sendmail, unless you're building
> your own, it would seem difficult to keep SCO servers up-to-date with
> such features. Or are you suggesting you would run hand-installed
> versions of Sendmail or Postfix on such servers?
>

Nope. Stock SCO with whatever sendmail is provided with the original
OS installation and applied patches.

This is really only applicable to small clients with low to medium
e-mail requirements. I've a lot of mom & pop businesses with legacy
accounting, accounting services (tax preparation), Law offices,
warehousing, or POS applications. Most have had their SCO systems before
the Internet was widely available. Over the years, we have replaced
old hardware with newer hardware and upgraded older versions of
SCO as needed.

Along with the upgrades, I've moved them from dial-up access
to their servers to SSH over the Internet and as a consequence of
obtaining Internet connectivity, registered their domains and tasked
the existing SCO server to handle low volume e-mail. These clients
were commonly using some_name@aol.com for their e-mail and now have
e-mail with their domain name.

I install spamassassin, fetchmail and procmail and configure them as
necessary to work on the client's system.

In larger environments, the client usually has on-site windows administrators
and have installed MS Exchange for e-mail. In those environments, I take
care of the UNIX and stand back as the MS guys do what they want to do.
I have one local city government client. They have one SCO UNIX box that
services the court system (well, the police department has a Unixware server
but I'm not involved with that box). The last time I was in their data center,
I counted over 60 Windows servers.

I've one law office where they were forced to move to E-mail service
provided by ElectricMail to obtain the necessary policy controls
on outgoing e-mail expeditiously to meet their client's required time
frame.

I live by the maxim: "you can't be all things to everyone." If it
fits on UNIX, I do it. If not, I network with other independent
consults to get the job done.


--
Steve Fabac
S.M. Fabac & Associates
816/765-1670

On Sat, Mar 08, 2008, Steve M. Fabac, Jr. wrote:
....
>I respect your experience and effort you have put into this subject.
>I am not trying to solve the world's spam problem. Just trying to
>protect my domain from being blacklisted due to the abuse perpetrated
>by others in faking the From: tag in their spam.

If this is your goal, forget it!

No competent/sane admin would *EVER* block a domain based on mail
in From: or From<space> headers as these are almost always bogus
in spam messages. A competent abuse person will look at Received
headers, checking IP addresses and domains, putting real trust
only in those inserted by their own mail servers or their trusted
MX servers which should deliver directly to the final MX.

If you have mail servers that host mailing lists, and send out
fairly large numbers of messages to AOL and similar major ISPs,
they generally have feedback loops where one can notify the ISP
of your legitimate servers, and they will notify you of spam
complaints from their users. Notifications will obfuscate their
user's e-mail addresses so one should user VERP or similar means
that create headers with the recipient's e-mail address allowing
you to remove the complainer from your list(s).

The URL for AOL's feedback loop is:

http://postmaster.aol.com/fbl/index.html

Bill
--
INTERNET: bill@celestial.com Bill Campbell; Celestial Software LLC
URL: http://www.celestial.com/ PO Box 820; 6641 E. Mercer Way
FAX: (206) 232-9186 Mercer Island, WA 98040-0820; (206) 236-1676

The meek shall inherit the Earth, the rest of us will go to the stars...
-Dr. Isaac Asimov