Very large amount of SPAM to random recipients to one domain

[chema_h]

I have a particular problem with just only one domain recently hosted at our server. It receive a very large amount of emails (>35.000) to random recipients that appears like this: "random_name"@domain.com

MagicSpam block them but I just can't understand why or how is this happening? Can we do something else to stop it?

At same time, when we started to host this domain, it began to appears this kind of emails messed at server queue:

Received: by OURSERVERDOMAIN.COM (Postfix)
id CD606DEB; Wed, 18 Apr 2012 16:25:52 +0200 (CEST)
Date: Wed, 18 Apr 2012 16:25:52 +0200 (CEST)
From: MAILER-DAEMON@OURDOMAIN.COM (Mail Delivery System)
Subject: Undelivered Mail Returned to Sender
To: MeaganValladolid@isdn.net.il
Auto-Submitted: auto-replied
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
boundary="3CED25D2.1334759152/s16097054.onlinehome-server.info"
Message-Id: <20120418142552.CD606DEB@s16097054.onlinehome-server.info>


MagicSpam reduced a lot this mess but we still receive 20-30 of them every day (before MagicSpam it was thousands a day).

I'll really appreciate any advice! Thx

[magicspam]

Hello,

Are the emails being sent from a specifc email address or does it seem to be distributed?

If you can provide some of the log lines from MagicSpam related to these emails we will get a better understanding of what is going on.


Also, there is a 'Pro' version of MagicSpam on the horizon which implements inbound and outbound rate limiters to help mitigate outbreaks like this.

[chema_h]

Seems that they are testing recipients but doesn't find the good address:

[magicspam]

Hello,

It apears as though the offending address is 178.46.121.212.
This address is listed on many block lists as show the below lookup on mxtoolbox.com
http://www.mxtoolbox.com/SuperTool.aspx ... 46.121.212

We recomend enabling the PSBL list in MagicSpam and see that cuts down on the uncaught spam.