  In this paper we continue previous efforts in the literature to determine
phenomenological values for the gluon mass by confronting theoretical results
obtained in a theory of massive gluons with experimental values or results
directly referring to the nontrivial structure of the Yang-Mills vacuum, e.g.
to the presence of the gluon condensate. The decays of heavy quarkonia into 3
gluons and 2 gluons + photon are considered in detail as well as the
correlators of the electromagnetic current and the scalar glueball current.
Based on the analysis for the latter quantities a value for the gluon mass in
the range of 500-600 MeV is estimated from the standard SVZ-value of the gluon
condensate.
