Solved

Outbound spam issue

Posted on 2010-11-22
1
465 Views
Last Modified: 2012-05-10
After hours, the mail server is being hit with thousands of outbound spam messages coming from postmaster@domain.  Postmaster does not exist.  It's reaking havoc on our network, causing us to be blacklisted etc.  I have scanned every pc, checked for open relay, firewall is configured for all outbound smtp traffic to go thru mail server.  No matter what, mail keeps flooding network, usually after 5pm and on weekends.  
0
Comment
Question by:szagoria
[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
1 Comment
 
LVL 76

Accepted Solution

by:
Alan Hardisty earned 500 total points
ID: 34191091
You are probably on the receiving end of an NDR attack.

Please have a read of my Article that should help you resolve this problem by enabling Recipient Filtering:

http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/A_2556-Why-are-my-outbound-queues-filling-up-with-mail-I-didn't-send.html
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

While rebooting windows server 2003 server , it's showing "active directory rebuilding indices please wait" at startup. It took a little while for this process to complete and once we logged on not all the services were started so another reboot is …
This article explains how to install and use the NTBackup utility that comes with Windows Server.
In this Micro Video tutorial you will learn the basics about Database Availability Groups and How to configure one using a live Exchange Server Environment. The video tutorial explains the basics of the Exchange server Database Availability grou…
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…

733 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