How to whitelist a domain name in ASSP
Whitelisting an email address is when you signal to the spam filter that the email address in question is legitimate and not a spammer. Emails from whitelisted addresses will always be received successfully.
ASSP lets you whitelist all incoming emails from a certain domain name. The method for achieving this is much the same as for whitelisting a single email address.
Send an email to firstname.lastname@example.org (replacing yourdomain.com with your domain name), and in the body of the email just include the domain name you need to whitelist. This should be in the form of *@domain.com (where domain.com is the domain name to be whitelisted).