  We present a (sub)millimeter line survey of the methanol maser outflow
located in the massive star-forming region DR21(OH) carried out with the
Submillimeter Array (SMA) at 217/227 GHz and 337/347 GHz. We find transitions
from several molecules towards the maser outflow such as CH$_3$OH, H$_2$CS,
C$^{17}$O, H$^{13}$CO$^+$ and C$^{34}$S. However, with the present
observations, we cannot discard the possibility that some of the observed
species such as C$^{17}$O, C$^{34}$S, and H$_2$CS, might be instead associated
with the compact and dusty continuum sources located in the MM2 region. Given
that most of transitions correspond to methanol lines, we have computed a
rotational diagram with CASSIS and a LTE synthetic spectra with XCLASS for the
detected methanol lines in order to estimate the rotational temperature and
column density in small solid angle of the outflow where enough lines are
present. We obtain a rotational temperature of $28\pm 2.5$K and a column
density of $6.0\pm 0.9 \times 10^{15}$ cm$^{-2}$. These values are comparable
to those column densities/rotational temperatures reported in outflows
emanating from low-mass stars. Extreme and moderate physical conditions to
excite the maser and thermal emission coexist within the CH$_3$OH flow.
Finally, we do not detect any complex molecules associated with the flow, e.g.,
CH3OCHO, (CH3)2CO, and CH$_3$CH$_2$CN.
