I used to be able to sort messages by "Order Received" WITHOUT displaying it as a COLUMN in the display. NOW - if I don't have "Order Received" displaying as a column, the "Order Received" sort option is "greyed-out"! For me, at least, the information showing in the "Order Received" column is useless and unwanted, and I hate to waste COLUMN SPACE to display information that I don't need. Please allow users to sort our messages by "Order Received" WITHOUT having to display it in a column. Thanks! :-) Since I initially wrote the above text, someone made the following suggestion which helped a lot, but didn't SOLVE the problem: As with your problem the sort option for "Order Received" is greyed out. I have managed to fudge it by displaying the "Order Received" column, enabling the sort by "Order Received" then "undisplaying" the "Order Received" column. The sort order is retained. I'm requesting that Thunderbird Supernova programmers please FIX the program so it can sort by any possible category REGARDLESS of whether a column is/was displayed for it. Thanks very much! :-)