Solved

Exchange 2007 becomes spam machine when enabling smarthost

Posted on 2011-02-25
3
715 Views
Last Modified: 2012-05-11
OK....here's one for the grownups.

We have a client that's signed up for the mx-logic anti-spam service. Part of their account is outbound filtering and requires the installation of a smarthost. No problem.

The problem is that when I enable the smarthost and disable the normal send connector the server starts sending out buckets of spam.

Malware bytes didn't come up with anything on the server, spybot search and destroy didn't come up with anything. The server isn't a relay but like clockwork, we change the send connector and it starts spamming. Message log
0
Comment
Question by:taiell0
3 Comments
 
LVL 15

Accepted Solution

by:
markdmac earned 500 total points
ID: 34987121
Sounds like you are allowing all workstations that authenticate to relay. You most likely have one or more workstations that are infected and are sending spam out via outlook.
0
 
LVL 27

Expert Comment

by:davorin
ID: 34992347
In addition to previous post:
How do you have smtp receive conectors configured?
You can set TLS encryption for client receive connector, so exchange will receive mails from SMTP clients on LAN over 587 port instead of port 25. In this way you should block sending from infected computers.
You can test open relay at www.mxtoolbox.com
0
 
LVL 76

Expert Comment

by:Alan Hardisty
ID: 34996795
Check your network with something like Wireshark to see if you have a machine sending out spam via port 25 to the server.

Check to see if you are an open relay on www.checkor.com

Alan
0

Featured Post

Are end users causing IT problems again?

You’ve taken the time to design and update all your end user’s email signatures, only to find out they’re messing up the HTML, changing the font and ruining the imagery. What can you do to prevent this? Find out how you can save your signatures from end users today.

Question has a verified solution.

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

We are happy to announce a brand new addition to our line of acclaimed email signature management products – CodeTwo Email Signatures for Office 365.
Read this checklist to learn more about the 15 things you should never include in an email signature.
In this video we show how to create a Resource Mailbox in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: Navigate to the Recipients >> Resources tab.: "Recipients" is our default selection …
This video discusses moving either the default database or any database to a new volume.

920 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

16 Experts available now in Live!

Get 1:1 Help Now