Mac Mini Sever - Public Share - how enable read and write permissions for new remote files

Hi, this Sunday a friend ask me to help hum with a problem on is Man Mini Server. He has a small office and uses the mini server to share a public folder to all his employees.

Everyone that creates a file, saves it to the public folder at the mini mac.

That problem is that, who creates the file owns it and remains with read-only permissions to everyone else. The owner has to change the file permission in order to the rest of the employees can work on it.

I do not know mac arquitecture, I only work with windows and linux, but i suspect the principles are the same.

We try to create another folder , and share it, but it happens the same. Have you any ideas on what is wrong?

I suspect it has anything to do with de file Sharing at the mini mac, but it has read and write permissions for everyone. Thanks for your help.