What happens to block listed address/IP/domain mails?

[bsrinu001]

Hi Team,

i would like to know, is any notification will be send to sender "or" recipient if we block list an address/IP/domain on our ESA?   

[Libin Varghese]

Connections rejected by a HAT mail flow policy return a SMTP code configured in the mail flow policy. For instance rejected connections by default return SMTP code 554. 

The server is possession of the email would then generate a notification based on the error code to let the sender know.

Regards,

Libin Varghese