can you return an email upopened?

[Terri]

I received an email from an undesirable person that I would like to return to
him... I know I can block him and I will from here on out, but I wondered if
it is possible to send the email back upopened so that he understands I do
not want emails from him.

 

[Roady [MVP]]

No, just delete it. Send him a separate mail informing him that all received
mails will be deleted unopened or simply ignore the mails altogether.
"Return to sender" is a snail mail feature.