Improve note in "Follow up" section

### Is your feature request related to a problem? Please describe.

As a Mail user, I want to know when I work with generated content. Follow-up reminders use AI to find out what needs a follow-up. This is not clear from the current UI note.

### Describe the solution you'd like

Improve the note

### Describe alternatives you've considered

_No response_

### Additional context

_No response_