Blacklisting is the name given to a list of email addresses from which you specifically do not want to receive messages.
Each blacklist entry can be either a complete email address or a partial email address with Pattern matching characters The characters * and ? when used in an address or string. e.g. *@domain.com, bob@domian.*, etc.
The action taken when detecting a blacklisted address depends on whether the filter is being applied at the SMTP or domain level.
SMTP
The senders address and entire message will be rejected. Any bounce
operations are handled by the sending server.
Domain
The filter policy specifies the action taken using the filter rules.
See: Filter Rules
See: Filter Blacklist,