I tried creating a case assign to the user but i am not receiving any mails for assignment and any update of the case
Notify on Assignment is not working when i create a case
Make sure that you have “Assignment Notifications” enabled in Admin > Email Settings
If you assign a case to yourself, you won’t receive any notification Email.
Also, Ensure that you have valid details entered in the Admin > Email Settings page.
You can click “Test Settings”, which will send a test email. This will allow you to check if the settings you have entered are valid
Also, something to note is that, if you navigate to the Email settings page, The password field can be cleared out, so make sure to enter this before saving Email Settings.
Do you still have Email issues if you enable Assignment notifications & Ensure you have valid and correct Email Settings?