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.