New Exchange 2010 server - error receiving emails

Hi guys,

I just set up a new Exchange Server 2010 on a new Windows Server 2008 box that I am getting ready for deployment. I've finished setting up the MX record for, and set up the port forwarding on the router, and my SMTP test checked out properly.

But upon trying to send an email to the main user, "" via my hotmail account, I get an error. The log is shown below:

OK, connected to
< 220 Venom.kleincs.local Microsoft ESMTP MAIL Service ready at Tue, 19 Oct 2010 15:49:11 -0400
< 250 Venom.kleincs.local Hello []
< 530 5.7.1 Client was not authenticated

I went into the receive connector and saw that I have two records in there:

"Client VENOM"
"Default VENOM"
(venom is the name of the server)

Inside both receive connectors, the "Anonymous Users" permission group is NOT checked, so anonymous users can't connect.

So my question is: Should I enable this? Will that solve the problem?

And how does this affect the security of my Exchange Server? Why was it disabled by default in the first place? It makes sense that emails from anonymous sources should be allowed in to the exchange server. So if I enable it is my exchange server still safe or is it now open as a conduit for anonymous users to send spam via it?

Lastly, should I enable the "Anonymous Users" permission group for "Client VENOM", or "Default VENOM", or both? What's the difference between the two?
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Rick FeeMessaging Engineer - Disaster Recovery EngineerCommented:
Yes you are required to enable anonymous on the Default need to modify the Client.   This will allow internet users to send to your server
Rick FeeMessaging Engineer - Disaster Recovery EngineerCommented:
Client Servername   This Receive connector accepts SMTP connections from all non-MAPI clients, such as POP and IMAP.

Default Servername   This Receive connector accepts connections from other Hub Transport servers and any Edge Transport servers you have.

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Rick FeeMessaging Engineer - Disaster Recovery EngineerCommented:
Well the only real way to stop or slow down spam to your users is to put a spam solution in place.    But spammers will not be able to relay off you if that is another question if you set the default connector to anonymous.    
Frosty555Author Commented:
>>But spammers will not be able to relay off you

That's what I was trying to figure out. Awesome thank you for your help
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