Parallels Plesk Panel: Spam Protection, Add White List
Add white list
If you want to be sure that you will not miss email from specific senders, type email addresses or domain names into the White list field.
Place each address in one row, or separate addresses with a coma, a colon, or a white space. You can use an asterisk (*) as a substitute for a number of letters, and question mark (?) as a substitute for a single letter. For example: email@example.com, firstname.lastname@example.org, *@mycompany.com. Specifying *@mycompany.com will add to the white list all email addresses that are under the mycompany.com mail domain.