Not receiving emails on Outlook 2007 on a company network domain.

I have added new users on a company network (server 2003). Also set up their new email addresses using Outlook 2007. Now both the new users are able to send emails but are not receiving any.

I tried sending them an email and it was returned with the following message:-

Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 5.1.1 <[email protected]>... User unknown (state 14).

How can I fix this error so that these users can receive emails?

All assistance highly appreciated

 

What happens when an email is sent from inside your domain?
I mean to these problem account...Also you mentioned using Outlook to set up the accounts? Surely you meant exchange or did you you build the email accts when setting up the user accounts in AD?

 

I'm new to this. I have found out that I have to first set up the email accounts on the email server which I didn't, then set up the email accounts on Outlook. I set up the accounts on Outlook only and not on the server. My assignment was to set up the users computers as clients on this domain and add the user accounts to the domain which I did successfully. Now I ran into this problem when I was setting them email accounts. To now they are sending but not receiving and from reading on ilopia.com, I learnt I have to set the accounts on the server.