Maybe it looks like a noob question, but I am looking for the answer.
It's mostly because of the weather and it affect games that are played outdoor. The question is what going to happen in your bet? For example, you bet on who's team are going to scored the first match. So if a team already scored and then the match is postponed, then your bet is a lost already.
But if your bet is like ML or handicap, once the game resume then your bet is on.
However, there could be some casinos that the moment that the game is cancelled or suspended, your bet is automatically voided.