On Epstein's zeta-function

Let $Q(x_1,x_2,x_3)=x^2_1+x^2_2+x^2_3$, and let $\zeta(s;Q)$ be Epstein's zeta-function of the form $Q$. It is proved that for $|t|>C>0$ one has the estimate
$$ \zeta(1+it;Q)\ll|t|^{1/4+\varepsilon}. $$