Exchange 2003 SP2 and SMTP virtual server anonymous connection?

When I open up Exchange system manager and go under the smtp virtual servers I noticed there is an option for anonymous smtp connections. This is enabled. Should this be deselected, and what is it's purpose? With it selected does it mean anyone can send an email message on the internet and they don't have to be authenticated on the Windows 200X system?

Thanks
john_s99Asked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
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.

MikeeMiracleCommented:
This is by design and default behaiviour.  When someone sends you an e-mail, their server
connects annonymously to your exchange servers SMTP server.  If you removed this setting then any server wishing to send e-mail to you would have to authenticate to Exchange first with correct login details before exchange would accept mail from them.  As no mail servers on the internet would be configured with logon details for your exchange server, you will recieve no e-mail.

If anything, some people advise that you should remove everything but the annonymous.  The reason for this is that by default you CAN try to authenticate to the SMTP server.  This means that someone could mount a dictionary attack on the server, hence this can be viewed as a security issue.  As all internet mail server deliver e-mail annonymously, no internet e-mail is affected if you remove the other authentication options.

I think you have confused this setting with mail relaying which allows people to send mail without first authenticating to your server.  Mail relaying is not permitted in Exchange 2003 by default.

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
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
Storage Software

From novice to tech pro — start learning today.