You can use the Hyperlink formula to open the email as given below. Just change the Email id, Subject, and body as per your requirements.
You can use the Hyperlink formula to open the WhatsApp chat window in your default web browser. You need to change YY with country code and XXXXXXXXXX with mobile number. Change the default text also. For the first time, you need login into your web WhatsApp after scanning the QR code.