Outlook on Laptop and Desktop

I work for a school district in which we use an Exchange server for our email needs, I ran to this issue a while ago and never really seemed to understand it.

1. Setup up teacher email on a desktop computer.
2. Setup up teacher email on a laptop, as soon as i hit “Send and Receive”, the email from the desktop was gone and sent it to the laptop.
3. Every email that was sent to that teacher was all going to laptop and not the desktop.

Any suggestions where i went wrong?