  XMM-Newton archival observations of the Be/X-ray binary candidate RX
J0103.6-7201 revealed pulsations with a period of ~1323 s. This makes RX
J0103.6-7201 the X-ray pulsar with the longest period known in the Small
Magellanic Cloud (SMC). More than 150 X-ray observations of RX J0103.6-7201 by
ROSAT, Chandra and XMM-Newton show flux variations by a factor of 50 on time
scales of days to years. Using the accurate positions obtained from ACIS-I
images the optical counterpart is identified with a V = 14.6 mag emission line
star. EPIC spectra of RX J0103.6-7201 above 1 keV are consistent with an
absorbed power-law with column density between (6-9)x10^21 cm^-2, except during
one observation when an extraordinary high value of 1.1x10^23 cm^-2 was
measured which strongly attenuated the power-law emission below 3 keV. A soft
excess between 0.5 and 1.0 keV is evident in the spectra which becomes best
visible in the highly absorbed spectrum. The soft component can be reproduced
by a thermal plasma emission model with its luminosity strongly correlated with
the total intrinsic source luminosity. Including results from three other SMC
Be/X-ray binaries extends the linear correlation over three orders of magnitude
in source intensity, strongly suggesting that the same mechanism is responsible
for the generation of the soft emission.
