How to block messages that come with my domain name

Eloy · Joined: 06 Aug 2007 Posts: 1

Dear folks:

Recently I am receiving in my Exchange Server 2000 any kind of bulk messages directed to my users coming from the Internet using my domain name. My users know that they don't want to open messages coming from people in other domains, but now that they receive messages from "james@ourdomain.com" they don't know if open it or not, and of course, you have the people that open it anyway.

I know that in other mail systems, when you try to send a message faking a user in that domain, the system request an authentification. I haven't found that in the Exchange. Do you have any idea of how can I perform that task? Thanks in advance.

Archived from group: microsoft>public>exchange2000>connectivity

Danny Luong [MSFT] · Joined: 06 Aug 2007 Posts: 3

Hi Eloy,

One preventive measure which can reduce as much as 80% of spam is setting up
your firewall or relay servers (or a network appliance) to perform PTR
record lookup (reverse DNS lookup) on all inbound port 25 communications.
Spammers do not usually have PTR records or correct ones, so their
connections to your environment would be dropped at the firewall (less load
on your E2k). In your case, the PTR would fail because they will not have
their PTR as your domainname.com.

--
Regards,
Danny Luong

Exchange Enterprise Messaging Connector Engineer
v-dannyl@online.microsoft.com
Please do not send email directly to this alias. This is for newsgroup
purpose only.

This posting is provided "AS IS" with no warranties, and confers no rights."
--------------------------------
"Eloy" wrote in message@microsoft.com...
> Dear folks:
>
> Recently I am receiving in my Exchange Server 2000 any kind of bulk
messages directed to my users coming from the Internet using my domain name.
My users know that they don't want to open messages coming from people in
other domains, but now that they receive messages from "james@ourdomain.com"
they don't know if open it or not, and of course, you have the people that
open it anyway.
>
> I know that in other mail systems, when you try to send a message faking
a user in that domain, the system request an authentification. I haven't
found that in the Exchange. Do you have any idea of how can I perform that
task? Thanks in advance.

Trapulo · Joined: 05 Aug 2007 Posts: 1

Ok, but this doesn't respond to Eloy's request Smile

I have the same problem. I've tried to block some sender (eg
admin@ourdomain.com) in exchange configuration, but this messages are still
arriving... Sad

"Danny Luong [MSFT]" wrote in message@TK2MSFTNGP10.phx.gbl...
> Hi Eloy,
>
> One preventive measure which can reduce as much as 80% of spam is setting
up
> your firewall or relay servers (or a network appliance) to perform PTR
> record lookup (reverse DNS lookup) on all inbound port 25 communications.
> Spammers do not usually have PTR records or correct ones, so their
> connections to your environment would be dropped at the firewall (less
load
> on your E2k). In your case, the PTR would fail because they will not have
> their PTR as your domainname.com.
>
> --
> Regards,
> Danny Luong
>
> Exchange Enterprise Messaging Connector Engineer
> v-dannyl@online.microsoft.com
> Please do not send email directly to this alias. This is for newsgroup
> purpose only.
>
> This posting is provided "AS IS" with no warranties, and confers no
rights."
> --------------------------------
> "Eloy" wrote in message
> @microsoft.com...
> > Dear folks:
> >
> > Recently I am receiving in my Exchange Server 2000 any kind of bulk
> messages directed to my users coming from the Internet using my domain
name.
> My users know that they don't want to open messages coming from people in
> other domains, but now that they receive messages from
"james@ourdomain.com"
> they don't know if open it or not, and of course, you have the people that
> open it anyway.
> >
> > I know that in other mail systems, when you try to send a message
faking
> a user in that domain, the system request an authentification. I haven't
> found that in the Exchange. Do you have any idea of how can I perform
that
> task? Thanks in advance.
>
>

Danny Luong [MSFT] · Joined: 06 Aug 2007 Posts: 3

RFC standard requires all mail servers to accept mails destine for their
domainname.com even if the username is incorrect.

You can reduce the spam by following the previous recommendation. If you
choose to use 3rd party content filtering software, please install them on a
machine not running Exchange, otherwise, you will run into a host of
problems including reinstalling Exchange.

--
Regards,
Danny Luong

Exchange Enterprise Messaging Connector Engineer
v-dannyl@online.microsoft.com
Please do not send email directly to this alias. This is for newsgroup
purpose only.

This posting is provided "AS IS" with no warranties, and confers no rights."
--------------------------------
"Trapulo" wrote in message@TK2MSFTNGP11.phx.gbl...
> Ok, but this doesn't respond to Eloy's request Smile

> I have the same problem. I've tried to block some sender (eg
> admin@ourdomain.com) in exchange configuration, but this messages are
still
> arriving... Sad

>
>
>
> "Danny Luong [MSFT]" wrote in message
> @TK2MSFTNGP10.phx.gbl...
> > Hi Eloy,
> >
> > One preventive measure which can reduce as much as 80% of spam is
setting
> up
> > your firewall or relay servers (or a network appliance) to perform PTR
> > record lookup (reverse DNS lookup) on all inbound port 25
communications.
> > Spammers do not usually have PTR records or correct ones, so their
> > connections to your environment would be dropped at the firewall (less
> load
> > on your E2k). In your case, the PTR would fail because they will not
have
> > their PTR as your domainname.com.
> >
> > --
> > Regards,
> > Danny Luong
> >
> > Exchange Enterprise Messaging Connector Engineer
> > v-dannyl@online.microsoft.com
> > Please do not send email directly to this alias. This is for newsgroup
> > purpose only.
> >
> > This posting is provided "AS IS" with no warranties, and confers no
> rights."
> > --------------------------------
> > "Eloy" wrote in message
> > @microsoft.com...
> > > Dear folks:
> > >
> > > Recently I am receiving in my Exchange Server 2000 any kind of bulk
> > messages directed to my users coming from the Internet using my domain
> name.
> > My users know that they don't want to open messages coming from people
in
> > other domains, but now that they receive messages from
> "james@ourdomain.com"
> > they don't know if open it or not, and of course, you have the people
that
> > open it anyway.
> > >
> > > I know that in other mail systems, when you try to send a message
> faking
> > a user in that domain, the system request an authentification. I
haven't
> > found that in the Exchange. Do you have any idea of how can I perform
> that
> > task? Thanks in advance.
> >
> >
>
>

Alfons Bierbaum · Joined: 05 Aug 2007 Posts: 1

Hi,
you should give my NoSPAMProxy a try. You find it as freeware on Simtel.net.
Alfons

"Eloy" schrieb im Newsbeitrag@microsoft.com...
> Dear folks:
>
> Recently I am receiving in my Exchange Server 2000 any kind of bulk
messages directed to my users coming from the Internet using my domain name.
My users know that they don't want to open messages coming from people in
other domains, but now that they receive messages from "james@ourdomain.com"
they don't know if open it or not, and of course, you have the people that
open it anyway.
>
> I know that in other mail systems, when you try to send a message faking
a user in that domain, the system request an authentification. I haven't
found that in the Exchange. Do you have any idea of how can I perform that
task? Thanks in advance.

anonymous · Joined: 06 Aug 2007 Posts: 1

We are experienceing something similar to this, except
that the spam email with our domain name in the header
(like anything@ourdomain.com)as the return path email had
been sent to many recipient on the internet with the
consequence to sending us all the notification from all
the postmaster, mailer-deamon etc. everywhere.

Our Exchange server is now running terribly slow, having
to receive these notifications from everywhere.

HELP US!!!
>-----Original Message-----
>RFC standard requires all mail servers to accept mails
destine for their
>domainname.com even if the username is incorrect.
>
>You can reduce the spam by following the previous
recommendation. If you
>choose to use 3rd party content filtering software,
please install them on a
>machine not running Exchange, otherwise, you will run
into a host of
>problems including reinstalling Exchange.
>
>--
>Regards,
>Danny Luong
>
>Exchange Enterprise Messaging Connector Engineer
>v-dannyl@online.microsoft.com
>Please do not send email directly to this alias. This
is for newsgroup
>purpose only.
>
>This posting is provided "AS IS" with no warranties, and
confers no rights."
>--------------------------------
>"Trapulo" wrote in message
>@TK2MSFTNGP11.phx.gbl...
>> Ok, but this doesn't respond to Eloy's request Smile

>> I have the same problem. I've tried to block some
sender (eg
>> admin@ourdomain.com) in exchange configuration, but
this messages are
>still
>> arriving... Sad

>>
>>
>>
>> "Danny Luong [MSFT]"
wrote in message
>> @TK2MSFTNGP10.phx.gbl...
>> > Hi Eloy,
>> >
>> > One preventive measure which can reduce as much as
80% of spam is
>setting
>> up
>> > your firewall or relay servers (or a network
appliance) to perform PTR
>> > record lookup (reverse DNS lookup) on all inbound
port 25
>communications.
>> > Spammers do not usually have PTR records or correct
ones, so their
>> > connections to your environment would be dropped at
the firewall (less
>> load
>> > on your E2k). In your case, the PTR would fail
because they will not
>have
>> > their PTR as your domainname.com.
>> >
>> > --
>> > Regards,
>> > Danny Luong
>> >
>> > Exchange Enterprise Messaging Connector Engineer
>> > v-dannyl@online.microsoft.com
>> > Please do not send email directly to this alias.
This is for newsgroup
>> > purpose only.
>> >
>> > This posting is provided "AS IS" with no warranties,
and confers no
>> rights."
>> > --------------------------------
>> > "Eloy" wrote
in message
>> >
804A923A34E3@microsoft.com...
>> > > Dear folks:
>> > >
>> > > Recently I am receiving in my Exchange Server
2000 any kind of bulk
>> > messages directed to my users coming from the
Internet using my domain
>> name.
>> > My users know that they don't want to open messages
coming from people
>in
>> > other domains, but now that they receive messages
from
>> "james@ourdomain.com"
>> > they don't know if open it or not, and of course,
you have the people
>that
>> > open it anyway.
>> > >
>> > > I know that in other mail systems, when you try
to send a message
>> faking
>> > a user in that domain, the system request an
authentification. I
>haven't
>> > found that in the Exchange. Do you have any idea of
how can I perform
>> that
>> > task? Thanks in advance.
>> >
>> >
>>
>>
>
>
>.
>

Trev · Joined: 06 Aug 2007 Posts: 1

Maybe this will help:

http://support.microsoft.com/default.aspx?scid=kb;EN-
US;319356

Go to the access tab and click the relay button
>-----Original Message-----
>We are experienceing something similar to this, except
>that the spam email with our domain name in the header
>(like anything@ourdomain.com)as the return path email had
>been sent to many recipient on the internet with the
>consequence to sending us all the notification from all
>the postmaster, mailer-deamon etc. everywhere.
>
>Our Exchange server is now running terribly slow, having
>to receive these notifications from everywhere.
>
>HELP US!!!
>>-----Original Message-----
>>RFC standard requires all mail servers to accept mails
>destine for their
>>domainname.com even if the username is incorrect.
>>
>>You can reduce the spam by following the previous
>recommendation. If you
>>choose to use 3rd party content filtering software,
>please install them on a
>>machine not running Exchange, otherwise, you will run
>into a host of
>>problems including reinstalling Exchange.
>>
>>--
>>Regards,
>>Danny Luong
>>
>>Exchange Enterprise Messaging Connector Engineer
>>v-dannyl@online.microsoft.com
>>Please do not send email directly to this alias. This
>is for newsgroup
>>purpose only.
>>
>>This posting is provided "AS IS" with no warranties, and
>confers no rights."
>>--------------------------------
>>"Trapulo" wrote in message
>>@TK2MSFTNGP11.phx.gbl...
>>> Ok, but this doesn't respond to Eloy's request Smile

>>> I have the same problem. I've tried to block some
>sender (eg
>>> admin@ourdomain.com) in exchange configuration, but
>this messages are
>>still
>>> arriving... Sad

>>>
>>>
>>>
>>> "Danny Luong [MSFT]"
>wrote in message
>>> @TK2MSFTNGP10.phx.gbl...
>>> > Hi Eloy,
>>> >
>>> > One preventive measure which can reduce as much as
>80% of spam is
>>setting
>>> up
>>> > your firewall or relay servers (or a network
>appliance) to perform PTR
>>> > record lookup (reverse DNS lookup) on all inbound
>port 25
>>communications.
>>> > Spammers do not usually have PTR records or correct
>ones, so their
>>> > connections to your environment would be dropped at
>the firewall (less
>>> load
>>> > on your E2k). In your case, the PTR would fail
>because they will not
>>have
>>> > their PTR as your domainname.com.
>>> >
>>> > --
>>> > Regards,
>>> > Danny Luong
>>> >
>>> > Exchange Enterprise Messaging Connector Engineer
>>> > v-dannyl@online.microsoft.com
>>> > Please do not send email directly to this alias.
>This is for newsgroup
>>> > purpose only.
>>> >
>>> > This posting is provided "AS IS" with no warranties,
>and confers no
>>> rights."
>>> > --------------------------------
>>> > "Eloy" wrote
>in message
>>> >
>804A923A34E3@microsoft.com...
>>> > > Dear folks:
>>> > >
>>> > > Recently I am receiving in my Exchange Server
>2000 any kind of bulk
>>> > messages directed to my users coming from the
>Internet using my domain
>>> name.
>>> > My users know that they don't want to open messages
>coming from people
>>in
>>> > other domains, but now that they receive messages
>from
>>> "james@ourdomain.com"
>>> > they don't know if open it or not, and of course,
>you have the people
>>that
>>> > open it anyway.
>>> > >
>>> > > I know that in other mail systems, when you try
>to send a message
>>> faking
>>> > a user in that domain, the system request an
>authentification. I
>>haven't
>>> > found that in the Exchange. Do you have any idea of
>how can I perform
>>> that
>>> > task? Thanks in advance.
>>> >
>>> >
>>>
>>>
>>
>>
>>.
>>
>.
>

Eloy · Joined: 06 Aug 2007 Posts: 1

Thanks for your efforts, but even in RFC requires that
all mail servers accept messages for their domain.com I
have seen some email servers that require you to
authenticate in order to send mail as a user of that
domain. For example: You can telnet
on port 25 and try to send a mail
as admin@triara.com and the server will require you to
authenticate. Is this possible in Exchange?

Best regards,
Eloy

>-----Original Message-----
>Maybe this will help:
>
>http://support.microsoft.com/default.aspx?scid=kb;EN-
>US;319356
>
>Go to the access tab and click the relay button
>>-----Original Message-----
>>We are experienceing something similar to this, except
>>that the spam email with our domain name in the header
>>(like anything@ourdomain.com)as the return path email
had
>>been sent to many recipient on the internet with the
>>consequence to sending us all the notification from all
>>the postmaster, mailer-deamon etc. everywhere.
>>
>>Our Exchange server is now running terribly slow,
having
>>to receive these notifications from everywhere.
>>
>>HELP US!!!
>>>-----Original Message-----
>>>RFC standard requires all mail servers to accept mails
>>destine for their
>>>domainname.com even if the username is incorrect.
>>>
>>>You can reduce the spam by following the previous
>>recommendation. If you
>>>choose to use 3rd party content filtering software,
>>please install them on a
>>>machine not running Exchange, otherwise, you will run
>>into a host of
>>>problems including reinstalling Exchange.
>>>
>>>--
>>>Regards,
>>>Danny Luong
>>>
>>>Exchange Enterprise Messaging Connector Engineer
>>>v-dannyl@online.microsoft.com
>>>Please do not send email directly to this alias. This
>>is for newsgroup
>>>purpose only.
>>>
>>>This posting is provided "AS IS" with no warranties,
and
>>confers no rights."
>>>--------------------------------
>>>"Trapulo" wrote in message
>>>@TK2MSFTNGP11.phx.gbl...
>>>> Ok, but this doesn't respond to Eloy's request Smile

>>>> I have the same problem. I've tried to block some
>>sender (eg
>>>> admin@ourdomain.com) in exchange configuration, but
>>this messages are
>>>still
>>>> arriving... Sad

>>>>
>>>>
>>>>
>>>> "Danny Luong [MSFT]"
>>wrote in message
>>>> @TK2MSFTNGP10.phx.gbl...
>>>> > Hi Eloy,
>>>> >
>>>> > One preventive measure which can reduce as much as
>>80% of spam is
>>>setting
>>>> up
>>>> > your firewall or relay servers (or a network
>>appliance) to perform PTR
>>>> > record lookup (reverse DNS lookup) on all inbound
>>port 25
>>>communications.
>>>> > Spammers do not usually have PTR records or
correct
>>ones, so their
>>>> > connections to your environment would be dropped
at
>>the firewall (less
>>>> load
>>>> > on your E2k). In your case, the PTR would fail
>>because they will not
>>>have
>>>> > their PTR as your domainname.com.
>>>> >
>>>> > --
>>>> > Regards,
>>>> > Danny Luong
>>>> >
>>>> > Exchange Enterprise Messaging Connector Engineer
>>>> > v-dannyl@online.microsoft.com
>>>> > Please do not send email directly to this alias.
>>This is for newsgroup
>>>> > purpose only.
>>>> >
>>>> > This posting is provided "AS IS" with no
warranties,
>>and confers no
>>>> rights."
>>>> > --------------------------------
>>>> > "Eloy" wrote
>>in message
>>>> >
>>804A923A34E3@microsoft.com...
>>>> > > Dear folks:
>>>> > >
>>>> > > Recently I am receiving in my Exchange Server
>>2000 any kind of bulk
>>>> > messages directed to my users coming from the
>>Internet using my domain
>>>> name.
>>>> > My users know that they don't want to open
messages
>>coming from people
>>>in
>>>> > other domains, but now that they receive messages
>>from
>>>> "james@ourdomain.com"
>>>> > they don't know if open it or not, and of course,
>>you have the people
>>>that
>>>> > open it anyway.
>>>> > >
>>>> > > I know that in other mail systems, when you
try
>>to send a message
>>>> faking
>>>> > a user in that domain, the system request an
>>authentification. I
>>>haven't
>>>> > found that in the Exchange. Do you have any idea
of
>>how can I perform
>>>> that
>>>> > task? Thanks in advance.
>>>> >
>>>> >
>>>>
>>>>
>>>
>>>
>>>.
>>>
>>.
>>
>.
>

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