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Exchange RFC2821 compliant?

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jonr at destar

May 1, 2008, 12:14 AM

Post #1 of 7 (362 views)
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Exchange RFC2821 compliant?

Hello list,

I have a tarpit set up with a high priority, 99, mx record to catch a
few spammers. I had an issue where an Exchange 2003 server was trying
to connect to that mx rather than my lower two at 10 and 20. I have
been trying to find conclusively if Exchange is RFC 2821 compliant in
trying to the lowest priority first.

Has anyone else seen this type of behavior coming from an Exchange
serever on their systems? I am leaning to maybe a network issue on my
side but was also curious if it was not me and possibly a M$ "feature".

Sorry, for the OT question and thanks for any help,

Jon

eperea at walkereng

May 1, 2008, 6:15 AM

Post #2 of 7 (343 views)
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Re: Exchange RFC2821 compliant? [In reply to]

On Wed, Apr 30, 2008 at 11:14:28PM -0800, jonr[at]destar.net wrote:
> I have a tarpit set up with a high priority, 99, mx record to catch a
> few spammers. I had an issue where an Exchange 2003 server was trying
> to connect to that mx rather than my lower two at 10 and 20. I have
> been trying to find conclusively if Exchange is RFC 2821 compliant in
> trying to the lowest priority first.
>
> Has anyone else seen this type of behavior coming from an Exchange
> serever on their systems? I am leaning to maybe a network issue on my
> side but was also curious if it was not me and possibly a M$
> "feature".

I have all my work email forwarded from the corporate Exchange servers
to our old domain's qmail servers, and have never received a message on
the higher-mx server when the lower-mx server was available. This is
not conclusive proof, but at least I can say that since the introduction
of Exchange 5.5 it appears to work properly (in that respect).

jonr at destar

May 1, 2008, 9:48 AM

Post #3 of 7 (339 views)
Permalink

Re: Exchange RFC2821 compliant? [In reply to]

Quoting Emilio Perea <eperea[at]walkereng.com>:

> On Wed, Apr 30, 2008 at 11:14:28PM -0800, jonr[at]destar.net wrote:
>> I have a tarpit set up with a high priority, 99, mx record to catch a
>> few spammers. I had an issue where an Exchange 2003 server was trying
>> to connect to that mx rather than my lower two at 10 and 20. I have
>> been trying to find conclusively if Exchange is RFC 2821 compliant in
>> trying to the lowest priority first.
>>
>> Has anyone else seen this type of behavior coming from an Exchange
>> serever on their systems? I am leaning to maybe a network issue on my
>> side but was also curious if it was not me and possibly a M$
>> "feature".
>
> I have all my work email forwarded from the corporate Exchange servers
> to our old domain's qmail servers, and have never received a message on
> the higher-mx server when the lower-mx server was available. This is
> not conclusive proof, but at least I can say that since the introduction
> of Exchange 5.5 it appears to work properly (in that respect).
>

Thanks Emilio,

I suspect something else is going on but trying to find definitively
if M$ follows the "MUST"s in the RFC's has proven harder than I first
expected. I know they don't follow the "SHOULD"s as they have said as
much on their website. The server in question is an Exchange 2003
server and I am hoping it is a recent patch that caused it. The real
problem is is that I don't have access to the server and I am not
looking forward to setting one up this weekend.

Thanks again,

Jon

robertwolfe at localnet

May 1, 2008, 11:23 AM

Post #4 of 7 (339 views)
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Re: Exchange RFC2821 compliant? [In reply to]

On Thu, 1 May 2008 08:48:46 -0800
jonr[at]destar.net wrote:

> I suspect something else is going on but trying to find definitively
> if M$ follows the "MUST"s in the RFC's has proven harder than I first
> expected. I know they don't follow the "SHOULD"s as they have said as
> much on their website. The server in question is an Exchange 2003
> server and I am hoping it is a recent patch that caused it. The real
> problem is is that I don't have access to the server and I am not
> looking forward to setting one up this weekend.

I installed Exchange 2003 Server on my PDC at home. So far have not had a chance to test it with qmail yet. But, plans are in the works to do just that. Might I suggest a bare bones Exchange install without and M$ update$ first?

--
Robert Wolfe <robertwolfe[at]localnet.com | robert.wolfe[at]voyager.net>
Systems Administrator, LocalNet Corp/CoreComm Internet
http://www.localnet.com | http://www.core.com

eperea at walkereng

May 1, 2008, 2:59 PM

Post #5 of 7 (338 views)
Permalink

Re: Exchange RFC2821 compliant? [In reply to]

On Thu, May 01, 2008 at 08:48:46AM -0800, jonr[at]destar.net wrote:
> I suspect something else is going on but trying to find definitively
> if M$ follows the "MUST"s in the RFC's has proven harder than I first
> expected. I know they don't follow the "SHOULD"s as they have said as
> much on their website. The server in question is an Exchange 2003
> server and I am hoping it is a recent patch that caused it. The real
> problem is is that I don't have access to the server and I am not
> looking forward to setting one up this weekend.

Jon,

I mentioned Exchange version 5.5 when trying to think when I started
forwarding from Exchange, but the servers have been updated to 2003.

I'm not really familiar with Exchange, but I tried changing the MX
preference of a couple of domains and it seemed to follow the DNS
changes properly. I'm not sure what whe current patch level is, so if
you suspect a recent patch this may not be applicable.

Emilio

jonr at destar

May 1, 2008, 4:14 PM

Post #6 of 7 (338 views)
Permalink

Re: Exchange RFC2821 compliant? [In reply to]

Quoting Emilio Perea <eperea[at]walkereng.com>:

> On Thu, May 01, 2008 at 08:48:46AM -0800, jonr[at]destar.net wrote:
>> I suspect something else is going on but trying to find definitively
>> if M$ follows the "MUST"s in the RFC's has proven harder than I first
>> expected. I know they don't follow the "SHOULD"s as they have said as
>> much on their website. The server in question is an Exchange 2003
>> server and I am hoping it is a recent patch that caused it. The real
>> problem is is that I don't have access to the server and I am not
>> looking forward to setting one up this weekend.
>
> Jon,
>
> I mentioned Exchange version 5.5 when trying to think when I started
> forwarding from Exchange, but the servers have been updated to 2003.
>
> I'm not really familiar with Exchange, but I tried changing the MX
> preference of a couple of domains and it seemed to follow the DNS
> changes properly. I'm not sure what whe current patch level is, so if
> you suspect a recent patch this may not be applicable.
>
> Emilio
>

Hi Emilio,

It is Exchange 2003 specific. It seems to happen only when it tries to
resolve a domain that has more than one MX RR listed. It also does not
happen all the time, which makes it easy to track down(sarcasm). What
happens is that it doesn't resolve in the order that it should, it
should go from highest priority to lowest but it doesn't seem to
follow that logic. What the workaround has been is to either use your
ISP's dns or put a linux box in front of Exchange to resolve the
domains. Here is a website that has some Exchange admins discussing
and trying to fix the problem.

http://forums.msexchange.org/m_180038400/mpage_3/printable.htm

Hope that helps you in the future and thanks for helping me,

Jon

esther at bitranch

May 5, 2008, 8:41 AM

Post #7 of 7 (288 views)
Permalink

Re: Exchange RFC2821 compliant? [In reply to]

Funny thing -- I just wrote a blog post last week about Exchange and
its RFC compliance. Or at least that's where it started.

> The Standard Argument: Incorporating Internet Standards into the
> Design Process
> http://advice.cio.com/esther_schindler/the_standard_argument

On May 1, 2008, at 12:14 AM, jonr[at]destar.net wrote:

> Hello list,
>
> I have a tarpit set up with a high priority, 99, mx record to catch
> a few spammers. I had an issue where an Exchange 2003 server was
> trying to connect to that mx rather than my lower two at 10 and 20.
> I have been trying to find conclusively if Exchange is RFC 2821
> compliant in trying to the lowest priority first.
>
> Has anyone else seen this type of behavior coming from an Exchange
> serever on their systems? I am leaning to maybe a network issue on
> my side but was also curious if it was not me and possibly a M$
> "feature".
>
> Sorry, for the OT question and thanks for any help,
>
> Jon
>
>
>

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