The Addresses Blacklist is located at: Security » Security Settings » Screening. This list contains addresses that are not allowed to send mail traffic through your server. If a message arrives from an address on this list, it will be refused during the SMTP session. This is useful for controlling problem users. Addresses may be blacklisted on a per domain basis or globally (applied to all MDaemon domains).
Messages are refused if they are from the addresses listed here
This window displays all currently blacklisted addresses, listed by the domain that is blacklisting them.
Choose the domain with which this blacklisted address will be associated. In other words, what domain do you wish to prevent from receiving mail from the specified address? Choose "All Domains" from this list to blacklist the address globally.
Enter the address that you wish to blacklist. Wildcards are accepted, therefore "*@badmail.com" will suppress any message from any user at "badmail.com", and "frank@*" will suppress any message from any address beginning with "frank@", regardless of the domain the message is from.
Click this button to add the designated address to the black list.
Click this button to remove an entry that you have selected in the list.
Notify blacklisted senders that their message was refused
If selected, a message will be routed back to the blacklisted sender telling him or her that the message was refused.