Posting Comments to Records
You can post comments to records to communicate with other users. When you post a comment to a record, the notification is sent to the user specified in the notification setting for each app.
If you specify a user and then post a comment, regardless of the notification setting for the app, the notification is sent to the specified user under "To Me".
The Difference Between "To Me" Notifications and Other Notifications
However, the notification is not sent to users who do not have view permissions for the record.
Click on the right side of the Record Details screen.
Enter in a comment.
If necessary, specify the comment recipient.
Specifying Comment Recipients