Email reports are created separately for each user and are automatically sent. You are always up to date given relevant changes for you.
These changes are collected and trigger the email report:
New responsibility (profile or activity)
New activity plan dates
New status report
Status report solved/reopened
New effect plan values
You can easily turn the reports on and off in your user account.
Click on the menu icon at the bottom of the sidebar and then select Account.
At the top right you will find a button to turn the reports on and off.