grep -A 2 -B -2 "The mail system" mbox_file
grep -A 2 -B -2 "The mail system" mbox_file
-B-B is for priviousprevious lines , so no need to give -negative value.
grep -A 2 -B 2 "The mail system" mbox_file <<<This will work please check
Regards Mukesh Payghan
grep -A 2 -B 2 "The mail system" mbox_file # This will work please check