taken with a grain of salt

If something is taken with a grain of salt it means something you were just told such as an explanation or a story is heard by you by you have considerable doubt. While you are trying to acknowledge what was said and you want to give them the benefit of the doubt, you definitely dont agree with it entirely and have many doubts about what was said. You dont necessarily disagree, but you are keeping your mind open to the possibility it is not true or meaningful.