CodeTwo Exchange Rules Pro is capable of blocking selected messages if they match the criteria defined in Conditions. This can be used e.g. as an anti-spam filter. For example, you can block messages coming from specific senders or those that include keywords defined within Conditions and therefore must be considered as spam.
How to configure this action
To activate this action in a given rule, click Add in the Action tab and select Block message from the menu (Fig. 1.).
A new action named Block message will appear on the List of actions and a properties pane will open (Fig. 2.).
This particular action does not require any further configuration. All messages that meet the criteria specified in the Conditions tab will be blocked.
If you do not specify Recipients or Senders in Conditions, all incoming and outgoing messages will be blocked. As a result, you will not be able to either send or receive any messages both internally and externally. Please use this option wisely.