Help In Drafting A Professional Mail

Hi HR Gurus,
I just joined a small company and I m observing that certain things are not going well. People are taking leaves frequently and without informing their managers.
I need a help in drafting a mail. I want to send a mail to all the employees regarding taking leaves. Employees are taking leaves without informing their managers. They just inform their peers or friends and get away with it. So I want to draft a mail which should not be a warning but just a mail to let them know that they need to follow some procedure before taking leaves. Can u please help me with this. Its urgent.
Thanks
Anjali Chawla

"Hi All
It has been observed that Employees have been taking leaves without informing ie taking permission from their respective Managers. It is important to note here that you are entitled to leaves only after taking permission from your superiors rather than just informing your peers. Hence it is advised to follow a proper procedure and maintain professionalism"
You can add/remove something from the above message as per your suitability
I hope this helps.
Sam