Hello!
Sorry, the variable hist_1_back_sptotal does not exist. If you want to check the amount of SP bets placed on a selection after the market has been settled, you need to remember the selections with the "remember" trigger action (have "Remember selections' bets" ticked, remember under a name that includes the market id, e.g. "mysels_market_id"). Then refer to "mysels_market_id_back_sptotal" in the trigger that emails you the message for the total amount of SP bets placed on that selection before the off.