In The Icewarp Mail Server, you can create Different patterns that can be used in other parts of the system. An example of this is to create a Firewall Pattern that can be used to block connections from a specific location. (or to allow communication from specific locations). Below are the steps to create this example:

1- Go to [System] [Advanced] [Patterns].

2- Add a new pattern.

3- name it firewall.

4- In the Items, put the IP address that you want to be part of the pattern there. 

5- Save.

6- Go to [System] [Services] and then open up the Properties and go to the Access Tab.

7- Check the option to "restrict access to all services"

8- Change the Access type to "deny".

9- In the box for the IP addresses, put in [firewall]save the changes and then restart the SMTP services.