Most Trusted Sender entries will be email addresses. This means that mail from that address will bypass our spam checks, and go straight to your Inbox.
If you correspond frequently with many people in a small business or organization, it may help to make a entire domain a Trusted Sender. Please note that this should be used with caution — domains for common email providers like gmail.com, for example, should not be added as trusted domains.
Both server and network addresses are for IP addresses only.
Server addresses will let you make a particular IP address a trusted sender. All mail coming from that IP address will automatically be accepted.
Network addresses will let you make a particular subnet a trusted sender. All mail from that network will be accepted.
Generally, it will be more helpful to add an email or domain address to your Trusted Senders list. If you do add server or network addresses, please do so with extreme caution.