Preventing files with spaces and periods at the end from being copied to the server

[Boe]

Hello,

We have a lot of macs attaching to the server - they can create or copy
files with periods or spaces at the end. Once they are on the server, you
can't remove them from the server via PC, Mac or the server itself - even
after a reboot.

I'd like to make sure this never ever happens again. How do I prevent it?