To get to this page, go to Settings → Misc Settings -> Permissions.

This page lets you set sender whitelist & blacklist entries for all users.

 

These are the same as the sender & target whitelist & blacklist entries in the user settings.

When local users send messages then the target address is checked against the user's Target Whitelist and Target Blacklist entries for that particular user, and also against the Global Target Whitelist and Global Target Blacklist on this page.

The order of processing is:

1.Is the target address on the user's target whitelist? If so, the message is allowed.

2.Is the target address on the user's target blacklist? If so, the message is not allowed.

3.Is the target address on the global target whitelist? If so, the message is allowed.

4.Is the target address on the global target blacklist? If so, the message is not allowed.

5.Are the user target whitelist and global target whitelist both empty? If so, the message is allowed

6.The message is not allowed.

 

Similarly, when a message is sent to a local user, the sender's address is checked against the user's Sender Whitelist and Sender Blacklist entries for that particular user, and also against the Global Sender Whitelist and Global Sender Blacklist on this page.

The order of processing is the same as for sending messages except that the sender whitelist & blacklist are checked, rather than the target whitelist & blacklist.