  We report the results provided by the XMM-Newton observation of the X-ray
binary pulsar SXP59.0 during its most recent outburst in April 2017. The source
was detected at $f_{\rm X}$(0.2-12 keV) = 8$\times 10^{-11}$ erg cm$^{-2}$
s$^{-1}$, one of its highest flux levels reported to date. The measured pulse
period was $P_{\rm spin}$ = 58.949(1) s, very similar to the periods measured
in most of the previous observations. The pulsed emission was clearly detected
over the whole energy range between 0.2 and 12 keV, but the pulse profile is
energy dependent and the pulsed fraction increases as the energy increases.
Although the time-averaged EPIC spectrum is dominated by a power-law component
(with photon index $\Gamma = 0.76 \pm 0.01$), the data show an evident soft
excess, which can be described with the sum of a black-body and a hot thermal
plasma component (with temperatures $kT_{\rm BB} = 171^{+11}_{-14}$ eV and
$kT_{\rm APEC} = 1.09^{+0.16}_{-0.09}$ keV, respectively). Moreover, the EPIC
and RGS spectra show narrow emission lines due to N, O, Ne, Mg, and Fe. The
phase-resolved spectral analysis of the EPIC data shows that the flux of the
black-body component varies with the pulse phase, while the plasma component is
almost constant. We show that the black-body component can be attributed to the
reprocessing of the primary emission by the optically thick material at the
inner edge of the accretion disc, while the hot plasma component is due to a
diffuse gas far from the accretion region and the narrow emission lines of the
RGS spectrum are most probably due to photoionized matter around the accreting
source.
