In relation to contract enforceability, which of the following is NOT an essential element?

Mutual consent is indeed an essential element of contract enforceability. This means that all parties involved must agree to the terms of the contract and understand the implications of their agreement. This agreement is often referred to as a "meeting of the minds." For a contract to be enforceable, both parties must have a clear understanding of their obligations and rights as laid out in the agreement.

The other elements listed—consideration, legal capacity of the parties, and indemnity—play specific roles in shaping the enforceability of a contract. Consideration refers to something of value exchanged between the parties, while legal capacity ensures that the parties involved have the mental and legal ability to enter into a contract. Indemnity is also important but is more specific to certain types of insurance contracts and may not be universally required for all contracts to be enforceable. Therefore, while indemnity is relevant in specific contexts, it is not a foundation for all contractual enforceability, making it the least essential element among the options presented.