  Type IIP Supernovae (SNe) are expected to arise from Red Supergiant stars
(RSGs). These stars have observed mass-loss rates that span more than two
orders of magnitude, from $< 10^{-6}$ solar masses yr$^{-1}$ to almost $
10^{-4} $ solar masses yr$^{-1}$. Thermal bremsstrahlung X-ray emission from at
least some IIP's should reflect the larger end of the high mass-loss rates.
Strangely, no IIP SNe are seen where the X-ray luminosity is large enough to
suggest mass-loss rates greater than about $ 10^{-5} $ solar masses yr$^{-1}$.
We investigate if this could be due to absorption of the X-ray emission. After
carefully studying all the various aspects, we conclude that absorption would
not be large enough to prevent us from having detected X-ray emission from high
mass-loss rate IIP's. This leads us to the conclusion that there may be an
upper limit of $\sim 10^{-5} $ solar masses yr$^{-1}$ to the mass-loss rate of
Type IIP progenitors, and therefore to the luminosity of RSGs that explode to
form Type IIPs. This is turn suggests an upper limit of $\leq 19 $ solar masses
for the progenitor mass of a Type IIP SN. This limit is close to that obtained
by direct detection of IIP progenitors, as well as that suggested by recent
stellar evolution calculations. Although the statistics need to be improved,
many current indicators support the notion that RSGs above $\sim 19 $ solar
masses do not explode to form Type IIP SNe.
