elementary business solutions

Whitelist features are not available via Exchange Management Console (the GUI), so this will have to be completed via the Exchange Powershell.

Open powershell via the exchange menu item and run one of the following scripts, based on your requirement:

To check whats currently whitelisted (Bypassed Recipients):

Get-ContentFilterConfig

To whitelist a single email address:

$list = (Get-ContentFilterConfig).BypassedSenders
$list.add("new.mail@address.com")
Set-ContentFilterConfig -BypassedSenders $list

To whitelist an entire domain:

$list = (Get-ContentFilterConfig).BypassedSenderDomains
$list.add("domain.com")