A foul smell like the smell comes from some of my drains whenever it rains.

Check the traps to make sure they have water, a bad vent can siphon out the water. If the traps are full then lets try mom's recipe for cleaning drains. Mix 1/2 cup table salt with 1/2 cup baking soda and dump into the drain followed by a cup of vinegar, step back. The next day dump a bucket of really hot water down the drain. Write back to me the day the odor comes back, if it ever does