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Little question:

How can I block a specific MX entry for incomming mail adresses?

We have some unwanted mails from people who uses some kind freemailer service with and with mail domain. Only the MX entry is the same as from the freemailer.
Email MX Entry

I want to block the whole MX entry.

We are using only the POP3 retriever. So I want to set up the blocking that the message will be deleted directly on the server at our ISP or directly after downloading (flatrate, traffice is not a problem for us).

A local managment without public blacklists would be perfect.

Thanks for any help.

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I am not 100% sure if I understand you correctly, but if you want to block a certain sender domain on the server, you can do that by going to:

Content Filter > Spam Filter

Click "Add" to add a new filter

Enter a description (example: block

Choose "From" as a header

Choose "contains domain" as Type

Put as Content

Tick "Treat the message as spam and ignore it"

Press OK and then APPLY.

That should do the trick.

Regards, Pascal

Dexion AG - The Blackberry Specialists in Switzerland

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I know this way. But it does not work like we need it.

When you make a DNS lookup for the MX entry for you domain you will mostly find the MX entry of you Internet Provider if he host your website and the mail accounts. The MX entry will show your server when you receive the emails directly via SMTP and not with the POP3 retriever.

We have here some Freemailer with have a service for a mail-domain.
This means: the emails looks like it comes from a domain and not from a freemailer.

I want to exclude the mx entry from a freemailer directly, which would include all hosted domains on him.
Example: He has a freemailservice which shows all mails with ...<_at_>
If you have a payside on the mailadress would be ...<_at_> (or .com; .net....). Only the mx entry would show that he is hosted at

Thats what I want to block.
Every domain hosted on (for example) and not a single domain. We get unwanted mails from such a freemailer service. Each Mail comes from another domain. To block them all one by one is a timewasting job.

Blocking the whole MX entry would block everything and all on a Web/Email Hoster. Equal what Domainname would be used.

How can I set a MX entry as blacklistened (for SMTP and POP3). When I use the "from" setting as you have told, I could block only one domain of the Freemailer.

Thats the problem I have.

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OK, now I understand.

I don't think KMS can do that (i.e. checking MX records of the sender domain on the fly and then discard the message), but you can find out the sender's host from the mail headers.

In the example below, I could define that I don't want any mail from in the spam filter.

Return-Path: <klfnmedz<_at_>>
X-Spam-Status: No, hits=3.4 required=4.0
tests=BAYES_50: 1.567,HTML_70_80: 0.039,HTML_MESSAGE: 0.001,
X-Spam-Level: ***
Received: from ([])
for info<_at_>;
Fri, 3 Feb 2006 15:00:41 +0100
Received: from ([]) by
(Post.Office MTA v3.5.3 release 223 ID# 0-59140U1000L100S0V35)
with SMTP id za; Fri, 3 Feb 2006 15:58:43 +0200
Message-ID: <002601c6292c$ccda0feb$bcb3f357<_at_>fpeehtbtsvxk>
From: "Ihre Drogerie" <klfnmedz<_at_>>
Subject: Einkaufen ist so guenstig
Date: Fri, 3 Feb 2006 14:52:03 +0100
MIME-Version: 1.0

So, if you send me the headers of one of the unwanted mails (by clicking on "View Source") I can send you the filter you need to apply.

Best regards, Pascal

Dexion AG - The Blackberry Specialists in Switzerland

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Thank you for your help.

I must see if my boss agrees to give mail headers out of the office.

If not, could you please explain or show where to set these filers?

Example host:
MX entry for

And here the receiver part of one of these mails:
Received: from [] (
by ***this is our MX server*** (node=mxeu4) with ESMTP (Nemesis),
id 0MKqlY-1F4yKP3Z50-0004ej for<_at_>; Fri, 03 Feb 2006 11:38:10 +0100
Received: from ( [])
by (Postfix) with ESMTP id 94E2670AE8
for <xxxxx.xxxxxxx<_at_>xxxxxxxxx.xx>; Fri, 3 Feb 2006 11:38:09 +0100 (CET)
Received: from nm1 ( [])
by (Postfix) with SMTP id 757E1B9CEC
for <xxxxx.xxxxxxx<_at_>xxxxxxxxx.xx>; Fri, 3 Feb 2006 11:38:07 +0100 (CET)

An mx-lookup for the sender-domain says that the MX Entry is (so I want to block

- Blanked address of final receiver in our company.
- Blanked MX entry from our ISP

Thank you.

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I don't see in the header, so it might be difficult, but you can block mails that have

in the header. As I said an MX lookup is not possible.

So what you can do is, compare all the headers of the mails you don't want and see if there are hostnames, that always appear. They can be blocked.

Regards, Pascal

Dexion AG - The Blackberry Specialists in Switzerland
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