Solved

Spamming???

Posted on 2006-06-26
5
457 Views
Last Modified: 2010-03-06
I have turned up the logging on my SMTP Service and i see a lot of this...

This is an SMTP protocol error log for virtual server ID 1, connection #45560. The remote host "216.159.242.70", responded to the SMTP command "rcpt" with "550 5.1.1 User unknown  ". The full command sent was "RCPT TO:<saoyocxq@boelter-yates.com>  ".  This will probably cause the connection to fail.

Are people spamming through me?

0
Comment
Question by:eenlow
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 9

Expert Comment

by:Exchgen
ID: 16987124
You are right.....

If you find too many of the above events being generated, its an indication that someone is trying to harvest your address book to get names and email address of all valid users in your organization.

Please followup steps mentioned in the articles below to secure your environment;

How to prevent unsolicited commercial e-mail in Exchange 2003
http://support.microsoft.com/?kbid=821746

How to configure connection filtering to use Realtime Block Lists (RBLs) and how to configure recipient filtering in Exchange 2003
http://support.microsoft.com/?kbid=823866

TechNet Support WebCast: Fighting spam using Microsoft Exchange Server 2003
http://support.microsoft.com/?kbid=841058

A software update is available to help prevent the enumeration of Exchange Server 2003 e-mail addresses
http://support.microsoft.com/?kbid=899492

Please do consider using the software update to prevent email address harvesting.

Raghu
0
 
LVL 7

Expert Comment

by:december41991
ID: 16987144
Cause: Recipient Filtering had been enabled for "recipients not in the directory"

No one is spamming you :) atleast thats what I think.
If you really want to check try sending a mail to your self by telnet usung bogus email as sender.


Recipient Filtering
http://support.microsoft.com/default.aspx?scid=kb;en-us;823866


Regards
Dominic
0
 
LVL 7

Accepted Solution

by:
december41991 earned 500 total points
ID: 16987157
actually people are trying to but not able to:

4. Exchange Server determines whether the Filter recipients who are not in the Directory check box is selected on the Recipient Filtering tab of the Message Delivery Properties dialog box. If this check box is selected, and if the recipient does not appear in the Active Directory directory service, Exchange Server returns the following error message to the sender:
550 5.1.1 User unknown
 

Source:
Recipient Filtering
http://support.microsoft.com/default.aspx?scid=kb;en-us;823866

0
 

Author Comment

by:eenlow
ID: 16987165
it almost sounds like people are spamming me and my server is trying to send a kickback but i want to be sure, you know...

thanks
Eric
0
 
LVL 9

Expert Comment

by:Exchgen
ID: 16987178
USE SECOND LINK I GAVE YOU!!!

Connection filtering is a real nice feature and you would be away from most of the blacklisted IP's that are known to all small and big BLOCKLISTING companies.

Raghu
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Marketers need statistics and metrics like everybody else needs oxygen. In this article we explain how to enable marketing campaign statistics for Microsoft Exchange mail.
Unified and professional email signatures help maintain a consistent company brand image to the outside world. This article shows how to create an email signature in Exchange Server 2010 using a transport rule and how to overcome native limitations …
This video demonstrates how to sync Microsoft Exchange Public Folders with smartphones using CodeTwo Exchange Sync and Exchange ActiveSync. To learn more about CodeTwo Exchange Sync and download the free trial, go to: http://www.codetwo.com/excha…
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…

737 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question