Whether forwarding an email notifies the original sender depends on the email client and the email server settings. Some email clients have the option to notify the original sender when an email is forwarded, while others do not. Additionally, some email servers also have options to notify the original sender when an email is forwarded, but it's not a standard. It's also possible that the email client or server used by the original sender can detect that an email has been forwarded, but it doesn't notify the sender.
So in summary, whether forwarding an email notifies the original sender is not something that can be determined generally, it depends on the specific email client and server settings.