Question:

When I look at a notification email, why are previous agent notes being shown? I thought notes were supposed to be agents-only! I don't want users to see the content of notes.

Answer:

The fact that you see the notes in your email (as an agent) does not mean they're being seen by users. Agent notes are included in notification emails to agents, but not the emails users receive.

Remember that ticket emails are not being sent directly between agents and users; they go through Deskpro. Deskpro only includes the note history in the agent notifications. 

Please check the actual emails being received by users.