G Suite Admin Console > Apps > App Settings > G Suite (G Suite Core Services) > Gmail > Advanced settings > Routing section > Routing >

In #1 Messages to affect select Inbound and Internal – receiving.

In #2 Envelope filter select Only affect specific envelope senders > Single email address > and in Email address type the email address

For #3 > For the above types of messages do the following > Reject message

Finally, hit Save.