Mail rules

Hi there jamesfromcortez,

If you are having issues using rules in the Mail app on your Mac running macOS Catalina, let's first ensure you are following these steps from Use rules to manage emails you receive in Mail on Mac to create and use rules:

1. In the Mail app  on your Mac, choose Mail > Preferences, then click Rules.

To review an example of a rule, select a provided rule, then click Edit. To close the rule, click Cancel.

2. Click Add Rule, then type a name for the rule.

3. Indicate whether any or all of the conditions must be true for the rule to be applied to a message.

4. Specify the conditions.

To use different header fields in conditions, choose Edit Header List from the first pop-up menu. To add your own header, click the Add button  in the Message Headers window.

5. Choose actions to perform on messages that meet the conditions. To specify multiple actions, click the Add button .

You can use AppleScript scripts as rule actions.

6. When you’re done, click OK, then decide to apply rules to existing messages already in mailboxes or to new messages.

You can apply rules to existing messages later by choosing Message > Apply Rules.

If you've already selected Apply Rules and this function completes, that may be why this option is greyed out since the rules have already been applied and there are no more messages that need to have the rules applied to them.

If something else is occurring, please provide more details so that we can continue to assist.

Cheers!