I want to attach a little note on some conversations, for reference/summarization/etc.
It is not yet built-in but Google is I think collecting enough votes for this feature.
There's a third-party app but I don't want to have to trust/rely on anybody for this.
Is there anything that could achieve the original purpose?
Case in point: I've an order placed and received tracking info via email, and I want to add a direct link to the tracking page to that email.
Best Answer
If you use Google's Task List, you could add the message as a Task and add notes to that.
"Add to Tasks" is under the "More" menu.
It's then added to your tasks, with a convenient link to open the original email message.
Then you can edit the task and add information to the "Notes" field.