Microsoft Exchange is a client server that holds all the mailboxes in your company. From time to time, you may experience networking issues with Exchange. You may notice that your Outlook e-mail is failing to connect to the server, and unable to retrieve and send e-mails. This problem typically occurs because your Exchange server requires RPC encryption. RPC stands for Remote Procedural Call. It determines encryption levels in your Exchange server. You will need a PC server computer to execute this task.
Click the "Start" menu and select "Control Panel." Click to switch it to "Classic View."
Click "Show Profiles."
Click to highlight your existing profile and select "Properties."
Click "Email Accounts."
Choose "Microsoft Exchange Server" and click "Change."
Click "More settings."
Click the tab labelled "Security."
Check "Encrypt data between Microsoft Office Outlook and Microsoft Exchange." Click "OK."
Click "Next." Select "Finish." Close the dialogue box.
Restart your PC server/administrator computer.