Re: Recommend NT mail server

Mitchell B. Wagers ( (no email) )
Tue, 17 Feb 1998 06:41:08 -0800

You have a valid point, but that isn't the case. I, personally, could send
mail back and forth and have it get caught. I think you left out or
misread one of the important things only grabs mail for domains
that it has listed for it's local domain this:

EMWAC on Server1 is setup for:

Post.Office on Server2 is setup for:

DNS Points (MX) to Server2 for:

The only thing in common here is, hosted on both machines,
but only Server2 is truly designated for mail to that domain. Server1 is
also Primary DNS, while Server3 (wherever) is Secondary DNS. I've sent mail
from Eudora, using for mail that is destined for, and it's shot down at Server1 due to an invalid user.
But, the mail is actually destined for Server2 because of the MX record in

Now, I understand the NS record situation, which *could* be the issue here,
but that's very doubtful. With that scenario above, mail FIRST arrives at
the deliver box on Server1 by EMWAC recieving the SMTP message, the rest is
up to to EMWAC to run the MX lookup for, instead of assuming
itself as the primary host. The resolution is to remove the "local domain"
from EMWAC's database and then all is well! Well, that's great, but as I
said, what if you have prioritized servers handling the same domains and
EMWAC just happens to be MX 100 (10, 20, 30, so on...), but picking up ALL
the mail.

So let's say our MX records are screwed up...I can start a fresh DNS server
and generate this same problem. I can add new domains that have no records
anywhere, and duplicate this problem. Obviously, the problem lies with
EMWAC...Please read carefully the entire situation and note the part about
which domains are where and where the mail is sent from. Then, read what
you wrote about MX and NS records and who's responsibility it is to perform
the routing functions (you are right, it only supports the problem in this

Just as a last note...I haven't experimented with any new betas of EMWAC,
but at last check it did not distinguish between domains. In other words, can also get mail from I *am* hoping
that was fixed in newer versions. I somewhat understand that though, as the
NT SAM doesn't care what domain they are on; EMWAC looks to the NT
Database. Mail servers should allow addresses with the same user@ as long
as the domain is different (while being able to distinguish between AND, which is how Post.Office,
NTMail, and several others work. The only unique aspect should be the POP
account, which is regardless of any domain and cannot be duplicated.

I sound tired...I am tired. I'll be happy to carry this further or help you
duplicate the problems I had, whenever I get time...just drop me a note in
my personal box. I know how SMTP, POP, APOP, IMAP4 works...that's not a
problem, thanks.

At 10:37 AM 2/17/98 -0300, you wrote:
>Mitch Wagers,
>On 17 Feb 98 at 3:39, you wrote:
>> If you run EMWAC on your DNS Server it likes to just "grab" mail for
>> any domain listed in its local domain database. Even if you point
>> your MX records to an entirely different machine, some mail goes
>> through and some doesn't. If there's no user in EMWAC and it isn't
>> supposed to recieve mail by DNS records and it happens to decide to
>> pick up those 500 messages for that invalid user, it drops the
>> messages, thus you are left with explaining the loss of 500
>> messages.
>It's very very strange. I am running EMWAC IMS in my DNS server since
>February 1997. I've domains which are local and I also have domains
>which MX records point to other servers, even in other ISP and I have
>no problems with EMWAC.
>I think you should note that it's responsibility of the SMTP server
>sending mail to determine where the MX records for a domain points
>and to send mail to there. If your EMWAC server is receiving mail it
>shouldn't be, either your MX records aren't correct or the SMTP
>servers sending messages are using NS records where they should use
>MX. I am sure it's not an EMWAC fault.
>> I know, you shouldn't run mail on your DNS Server, but many do.
>Like I do.
>> On top of that cool *trick* it isn't very stable under a load and
>> has very minor SPAM protection. Although, it is a good program, it
>> is free and can get things going quickly.
>I don't want to start a flame war here, ok? As I said I'm running
>EMWAC IMS since a year ago without problem. I have more that 1000
>users accessing email through it and I am a very satisfied user.
>I suggest you to think about how email is sent over the Internet and
>you'll probably agree that if EMWAC is receiving mail which should go
>to other server, it's because the originator SMTP server sent the
>messages to the wrong machine.
>o-----------------( Jose Carlos da Silva )------------------o
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