Global search provides a single general text input from which to search. Near useless. I typed in a date, result includes hundreds of message, mostly having a few digits of the date somewhere in the msg body. F1 (help) is not context aware, so rather than focused help, that might provide some hints how to craft a detailed search from a single control, it takes us to the home page for documentation. Also: seems this is clearly not the forum to get anything done, as my prior inquiry is now archived. https://support.mozilla.org/en-US/questions/1353744#answer-1450482