Are you supposed to have washing machines serviced or cleaned?

I try to avoid going near the thing as much as possible, however recently it seems to leave a nasty damp smell on clothes and in the utility room.

I always treated them like an appliance you just use until it kicks the bucket and get another 1, however it works fine and is still relatively new (3-4 years)

So in short are you supposed to clean them or service them? (I hope its not a thing everyone does regularly, and passed me by) and if so how!

cheers