The filtering system has Friends (whitelist) and Enemies (blacklist) options available for your use to filter by email address, domain name, or IP address.
Whitelist and blacklist entries are not required to ensure that you do not receive spam. If there is a conflict between your whitelist entry and a blacklist entry for the entire domain set by your email administrator, then the domain-level setting takes precedence.
We do not recommend using whitelists and blacklists to manage email accounts because spammers have adopted techniques to send email from addresses within your own domain (including your own email address). Whitelists, in this case, would override the spam filter rule and result in the spam and viruses being delivered to you even though the system had identified it as spam. Similar unintended consequences can result from the use of blacklists.
To add to the Friends list (whitelist)
To add to the Enemies list (blacklist)
To remove an entry from the Friends list (whitelist)
To remove an entry from the Enemies list (blacklist)
The following screenshot shows a Friends list with one entry and an empty Enemies list: