To create a new rule, click  New Rule button on the Toolbar and make the appropriate settings in the Rule Settings window.

Enter the name of a new rule into the empty field. Then check the necessary options.

Do not process other rules for current message if this rule is successfully executed - check this option if you do not want the program to continue executing the rest of rules for the current message if this rule was successfully executed.

Delete message from server if this rule is successfully executed - check this option if you want the program to delete a message from the server if this rule was successfully executed.

Mark message as processed after rule is executed - check this option if you want the program to mark a message as processed after this rule was successfully executed.

Now select the accounts to collect incoming messages. If you did not create a POP3 account yet, click Accounts button to create it now.

Further you can add Filters, Field Extractor, Fields Processor, and Actions to your rule depending on how you want to process your emails.