Hi @Murat AKYÜREK
Welcome to our forum!
Based on your description, this notification email appears to be a delegate with the delegated user set up as a delegate for the manager's calendar, and the option to send a copy of the meeting-related message to the delegate is checked.
To dismiss this notification email, ask your manager to uncheck the option to send a copy of the meeting-related message to the agent.
Go to File > Account Settings > Delegate Access, select the delegate’s name, and click Permissions. Then, under Calendar, uncheck the box that says Delegate receives copies of meeting-related messages sent to me.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.