The text below is actually comments in the configuration file. Shown here so you know about the parameter and can set it correctly for your environment.
#
# number of worker threads allocated for the AService
# daemon. Optimally, it should be equal to the number of
# processors on the machine, unless an AService DLL does
# synchronous handling of connections (Imap and Pop
# Proxy do not).
#
default:NumThreads 2