<p>We consider a linear autonomous differential equation of neutral type and study the positivity of its fundamental solution and Cauchy function and establish two-sided exponential estimates for these functions. We prove that if the equation is exponentially stable and its characteristic function has at least one real root, then the fundamental solution and Cauchy function are positive on the positive half-axis. Based on this property, we construct two-sided exponential estimates with sharp exponents and coefficients.</p>