  Commutative supersymmetric Yang-Mills is known to be renormalizable for
${\cal N} = 1, 2$, while finite for ${\cal N} = 4$. However, in the
noncommutative version of the model (NCSQED$_4$) the UV/IR mechanism gives rise
to infrared divergences which may spoil the perturbative expansion. In this
work we pursue the study of the consistency of NCSQED$_4$ by working
systematically within the covariant superfield formulation. In the Landau
gauge, it has already been shown for ${\cal N} = 1$ that the gauge field
two-point function is free of harmful UV/IR infrared singularities, in the
one-loop approximation. Here we show that this result holds without
restrictions on the number of allowed supersymmetries and for any arbitrary
covariant gauge. We also investigate the divergence structure of the gauge
field three-point function in the one-loop approximation. It is first proved
that the cancellation of the leading UV/IR infrared divergences is a gauge
invariant statement. Surprisingly, we have also found that there exist
subleading harmful UV/IR infrared singularities whose cancellation only takes
place in a particular covariant gauge. Thus, we conclude that these last
mentioned singularities are in the gauge sector and, therefore, do not
jeopardize the perturbative expansion and/or the renormalization of the theory.
