MS Exchange 2003 smtp virtual server deny emails of local domain send from outside...

I have an email server MS Exchange 2003 with a default smtp virtual server...

Now it possible to telnet xxx 25 in this server, from outside the local network (from the internet) and send an email with "mail from" as xxx@YYY.com (where YYY.com is the domain name which this email server serves...)

Why is this happening?

How can I block any outsider from sending an email as it belongs to our domain?

I have checked my servers for open relay... with negative results...

Is this problem some kind of open-relay issue?

Thank you for your help...
agortsAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

mass2612Commented:
Hi,

What's your authentication setting set to under ESM > Your Exchange Org > Servers > Server name > Protocols > SMTP > Virtual SMTP node > Properties > Access Tab > Authentication.

You need to make sure annonymous is disabled. You also need to make sure you don't have any other virtual SMTP server connections setup on other servers or SMTP connectors that allow annonymous access.
0
agortsAuthor Commented:
Anonymous is checked!

If I disable it then I could not receive emails from other SMTP servers!
0
mass2612Commented:
Ok. You are directly accepting mail on purpose from the Internet to port 25 on your internal server. If you have a SMTP gateway on the DMZ this is configured with a username and password to authenticate therefore annon is not required.

Try checking your relay settings under the same area of ESM under the Access tab make sure that "Only the list below" is selected and that the list is empty or only has your internal servers that require it.

Do you have an  SMTP connector? Make sure if you have a * in the Address Space tab that "allow messages to be relayed.." is not enabled.
0
Has Powershell sent you back into the Stone Age?

If managing Active Directory using Windows Powershell® is making you feel like you stepped back in time, you are not alone.  For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why.

agortsAuthor Commented:
Yes in relay, "Only the list below" is selected and the list is empty... It is also checked the "Allow all computers which successfully authenticate to relay regardless of the list above"

No I do not have an SMTP connector...
0
MegaNuk3Commented:
If you are running Exchange 2003 SP2, then simply configure the Intelligent Message Filter as per:
http://www.petri.co.il/configure_imf_in_exchange_2003_sp2.htm

Then add "Sender Filtering" and filter messages from @YYY.com. You can then either archive them for checking later or just drop the connection. Sender filtering is talked about here: http://msexchangeteam.com/archive/2005/07/18/407838.aspx

This may affect external POP/IMAP users if you have any but you can setup a separate virtual SMTP server for them if needed...
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
agortsAuthor Commented:
I will look for this in the Symantec Mail Security for Microsoft Exchange...
0
MegaNuk3Commented:
Thanks for the upate and the points
0
agortsAuthor Commented:
I thank you for the help....
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Email Protocols

From novice to tech pro — start learning today.