Maintaining Unix permissions upon creation of new file/directory

[solaris]

Hi all,

I have a question regarding Unix permissions.
We are currently running hypermail v2.1.8 and we would like hypermail
to honour the user/group permissions created on the parent directory
for any subsequently created files or directories.

E.g. /hypermail/test has permissions of
nobody manage

nobody is the user
manage is the group

Newly created files and directories by hypermail inside of
/hypermail/test have permissions of
nobody nobody

nobody being both the user and the group.

Does anyone have any idea how to remedy this?

Thanks for your time.