Solved

NDR attack

Posted on 2011-03-17
4
876 Views
Last Modified: 2012-05-11
I have recently applied some known fixes to resolve an NDR attack but am unable to receive mail now but am able to send, would anyone have an idea of where I should be looking?  thank you in advance.
0
Comment
Question by:jmv973
  • 2
  • 2
4 Comments
 
LVL 76

Accepted Solution

by:
Alan Hardisty earned 500 total points
ID: 35162100
You have probably taken off the Anonymous Authentication from your Receive Connector / SMTP Virtual Server - that will kill your mail-flow dead in it's tracks.

What version of Exchange do you have?
0
 

Author Comment

by:jmv973
ID: 35162106
2003
0
 

Author Comment

by:jmv973
ID: 35162118
I have verified that it is enabled but still no luck?
0
 
LVL 76

Expert Comment

by:Alan Hardisty
ID: 35162136
Okay - if the Anonymous Authentication is enabled on your SMTP Virtual Server, then is port 25 open inbound on your firewall?

Check on http://www.canyouseme.org and test port 25.  You should see SUCCESS if all is well.

If that doesn't work - what did you change exactly, or what did you follow to eliminate the NDR attack?
0

Featured Post

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

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.
This article explains in simple steps how to renew expiring Exchange Server Internal Transport Certificate.
In this video we show how to create an Accepted Domain in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Mail Flow >> Ac…
The video tutorial explains the basics of the Exchange server Database Availability groups. The components of this video include: 1. Automatic Failover 2. Failover Clustering 3. Active Manager

706 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

Need Help in Real-Time?

Connect with top rated Experts

19 Experts available now in Live!

Get 1:1 Help Now