How do I prevent open relay but allow anonymous connections?

Posted on 2010-11-11
Medium Priority
Last Modified: 2012-05-10
I have a Microsoft Exchange 2003 server on MS Windows Server 2003. My server was sending out spam. I removed the anonymous access from the Access Control and now it isn't an open relay, but it appears as though external email is not being delivered. Did I do something wrong? Thanks.
Question by:leviatdr
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
  • 3
  • 2
  • 2
LVL 35

Assisted Solution

by:Ernie Beek
Ernie Beek earned 800 total points
ID: 34116415
read this one: http://www.amset.info/exchange/smtp-openrelay.asp

You can skip the part to check if you're an open relay ;-)

Expert Comment

ID: 34116429
You need enable the anonymous access. Click the RELAY button in the Access tab and make sure ONLY THE LIST BELOW is selected and no entries exist below that.

Author Comment

ID: 34116450
When I have Anonymous Access enabled, I can telnet into my mail server and send email without authentication. I went through the article above and could not resolve my issue. What else can I check?
Office 365 Training for Admins - 7 Day Trial

Learn how to provision tenants, synchronize on-premise Active Directory, implement Single Sign-On, customize Office deployment, and protect your organization with eDiscovery and DLP policies.  Only from Platform Scholar.


Accepted Solution

vanbarsoun earned 1200 total points
ID: 34116482
You will be able to send email to addresses in your domain without authentication, but not to other domains. Go here and check to see if your IP is relaying:

LVL 35

Expert Comment

by:Ernie Beek
ID: 34116550
' I went through the article above and could not resolve my issue'

How did you check?

Author Comment

ID: 34116643
I checked it by trying the commands through telnet from an external IP.

I was incorrect about being an open relay. It seems more like a compromised user account. I've enabled authentication logging, hopefully I can figure out where the bulk email came from. Anything else I should watch?

Author Closing Comment

ID: 34116656
My initial assumption was wrong. I was not a open relay. Further investigation is needed to find out why my mail server was sending out spam.

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

A list of top three free exchange EDB viewers that helps the user to extract a mailbox from an unmounted .edb file and get a clear preview of all emails & other items with just a single click on mailboxes.
There are times when we need to generate a report on the inbox rules, where users have set up forwarding externally in their mailbox. In this article, I will be sharing a script I wrote to generate the report in CSV format.
In this video we show how to create an Address List 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 Organization >> Ad…
This video discusses moving either the default database or any database to a new volume.
Suggested Courses
Course of the Month7 days, 21 hours left to enroll

765 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