The tone in the mail is stiff and unfriendly. The staff will feel that they are not respected when reading this mail. The writer should be more considerate and point out the problem more tactfully.

Rewritten Version for Reference:

Subject: Lunch hours

Dear all,

As you know, our lunch breaks are scheduled for an hour from 12:00 a.m. to 1:00 p.m..

Unfortunately, some staff have been extending this one-hour break, which has caused some inconvenience for others.

I realize that there will be times when you need a longer lunch break. On such occasions, please ensure appropriate cover in advance.

I’m sure you all understand the importance of observing our working hours.

Thank you very much for your cooperation.

Regards,

Anna