I use the “Add Note” feature quite a bit, in particular to keep an original request of mine attached to a reply by one of those services that a. only let you place a request via an online form and b. do not quote your request in their replies (hint: Amazon)
Looking around for a keyboard shortcut instead of having to run down to the bottom of the pop-down menu (at the upper right in a mail window) with the mouse, I couldn’t find one in the settings. Is there something that’s escaped me?
