I have used outlook on a laptop and desktop for years now with no problems.  Both run Microsoft.  I have just brought a Macbook Pro and set up Outlook on it, this took some time. Now  I can receive emails on all 3 devices no problem and send them, but if i open an email on the Macbook first the emails disappear from the other devices outlook, the contents of my in boxes on the Microsoft devices have also disappeared.  

It seems my Macbook has all of them in a file called On My Computer, the file that has my domain email (run from Roundcube) is pretty much empty.  I have looked at the settings and cannot find one that says - keep emails on server - or something similar that's been suggested.  The issue i have is that i still have to use the other devices from time to time and as it is a company email account i am talking about it is pretty important that i can do this.

Also of note, before i set up outlook on the Macbook i set up the Apple Email app and this worked fine with no problems and everything was sync'd ok.

Pretty long winded, but basically the Macbook outlook has taken all the emails from the server and i cannot access them from other devices.

Any help or suggestions very much welcome.

Rae Jiggins