  $^{75}$As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance
(NQR) measurements have been carried out to investigate the magnetic and
electronic properties of the filled skutterudite metallic compound
SrFe$_4$As$_{12}$. The temperature dependence of Knight shift $K$ determined by
the NQR spectrum under a small magnetic field ($\le$ 0.5 T) shows the similar
temperature dependence of the magnetic susceptibility $\chi$ which exhibits a
broad maximum at $T^\ast$ $\sim$ 50 K. The nuclear spin-lattice relaxation rate
divided by temperature, 1/$T_1T$, increases with decreasing temperature and
exhibits a broad maximum at $T$ $\sim$ 70 K, similar to the case of $\chi$. The
temperature dependence of $K$ and $1/T_1T$ is reasonably explained by a simple
model where we assume a concave-shaped band structure near the Fermi energy.
Based on a Korringa ratio analysis using the $T_1$ and $K$ data, ferromagnetic
spin fluctuations are found to exist in SrFe$_4$As$_{12}$. These results
indicate that SrFe$_4$As$_{12}$ can be characterized to be a metal with
ferromagnetic correlations and also the peculiar band structure responsible for
the suppression of $1/T_1T$ and $K$ at low temperatures.
