Is a mutual release always necessary?

[John Faarup]

If a contract has been signed (I am the seller) but no action was taken by the buyer (never sent a mortgage commitment, never did the inspection, etc) is it required a mutual release be signed by both parties before I can enter in an agreement with another person for sale of the home? The buyer broker just stopped answering my calls and emails even though I have asked him multiple times to send a mutual release.

The EMD is being held by the buyer broker (I am the listing broker) so I am not concerned about the dispersal. I've just never been in a situation where someone wouldn't sign one or simply stopped communicating. For all intents and purposes the contract is void because of the unfulfilled conditions, correct? Does that still necessitate a mutual release be signed?