Google domains registrar provides a free service to forward up to 100 e-mails from the custom domains. To enable this service navigate to Email tab in the Google Domains Console.
Specify the e-mail to forward from the in the first box and e-mail to forward to in the second box.
verification code will be sent to the destination e-mail. Until the e-mail is verified the forwarding is not enabled:
Once e-mail is verified the warning is removed:
Unlike forwarding with GoDaddy, Google Domains enables the encryption for the forwarded e-mails: