You can receive email messages from your email accounts on your Apple Watch.
Press the Digital Crown to go to the main menu.
Press the email icon.
Press arrow left.
Press the required email account.
Press the required email message.
Press the microphone icon and follow the instructions on the screen to record and send the message.
Press the required quick reply.
Slide your finger left on the required email message.
Press the Digital Crown twice to return to the home screen.