I am replacing our current pop mail server to Microsoft Exchange Server 2013. I installed it on a trial/test windows 2012 R2 Server. I have encountered some errors like the machine wasn't part of the domain, IIS and etc. like 20 errors in total but I got past that from the guide I've found online and I can access the EAC and manage the Exchange server. When i did a test on a new user I created, it didn't work like no send and receive at all so I went to Mail Flow and configured the Send Connector which internally it works but I can't receive any email which when I checked the Receive Connector there was a presetup stuff on it already which I'm assuming that it would work/correct. So the problem as far as I'm concern was, I can't send out any emails (internal/external) and for some whatever reason sometimes even the internal is not receiving it but all the time no outgoing from exchange mail.
Things I did and tried:
1. Added the new server to our DNS server
2. Added the new server to our gateway and configured the prechains, Forward and PreRouting
3. Added our dns server and gateway under Mail Flow and Send Connector.
Thanks in advance for whoever can help me sort out the problem.