user accounts and groups for the qmail binaries and such

[wolfgang zeikat]

i am about to install qmail in a fresh linux installation ...

while looking at the qmail installation i currently have i noticed that
all the qmail* users have /bin/bash as their login shell, same with the
user alias ...

is that necessary for the programm to work properly?
i rather tend to have */passwd or /bin/true as login shells for users and
am wondering if i could install the new qmail without that /bin/bash there

greetings
wolfgang