I'm trying to send Ether from an account of mine to a friend's account. I'm using the Ethereum Wallet application on Windows, my friend uses the Ethereum Wallet application on a Linux VM. The network seems to recognize the recipient account. When I send Ether to that account, transaction is completed on my side, but my friend never receives the Ether. Do you have any idea what could be the problem ?
Note: sending Ether from my account to another account of mine works well.