why does gmail accept and bounce ?

[Benny Pedersen]

Reporting-MTA: dns; ms1.greatbasin.net
Received-From-MTA: DNS; localhost
Arrival-Date: Mon, 2 May 2022 09:24:25 -0700
Final-Recipient: RFC822; mrsvete...@gmail.com
Action: failed
Status: 5.7.26
Remote-MTA: DNS; gmail-smtp-in.l.google.com
Diagnostic-Code: SMTP; 550-5.7.26 This message does not have 
authentication information or fails to
Last-Attempt-Date: Mon, 2 May 2022 09:24:27 -0700