You must login to the system to enter specific mail addresses or domains into your whitelist.

Click on Filter Rules

Then click on User Whitelist

To whitelist a specific mail address enter the address in the Sender Email: text box and click Add.

To whitelist a mail domain enter the domain in the Sender Domain: text box and click Add.

This would mean that anyone with an address @microsoft.com could send you mail without being quarantined. Whitelisting a domain in this way can allow spam through. Quite often spammers forge common domains as the from address. So e.g. if you whitelist gmail.com you may allow some spam through.