  A search for high-mass resonances in the $e^+e^-$ final state is presented
based on 2.5 fb$^{-1}$ of $\sqrt{s}=$1.96 TeV $p\bar{p}$ collision data from
the CDF II detector at the Fermilab Tevatron. The largest excess over the
standard model prediction is at an $e^+e^-$ invariant mass of 240 GeV/$c^2$.
The probability of observing such an excess arising from fluctuations in the
standard model anywhere in the mass range of 150--1,000 GeV/$c^2$ is 0.6%
(equivalent to 2.5 $\sigma$). We exclude the standard model coupling $Z'$ and
the Randall-Sundrum graviton for $k/\overline{M}_{Pl}=0.1$ with masses below
963 and 848 GeV/$c^2$ at the 95% credibility level, respectively.
