I am getting a lot of these failed delivery emails to my xtra account ....

Hello, this is the mail server on bisko.win.

I am sending you this message to inform you on the delivery status of a

message you previously sent.  Immediately below you will find a list of

the affected recipients;  also attached is a Delivery Status Notification

(DSN) report in standard format, as well as the headers of the original

message.

In the attachment...

Reporting-MTA: dns;bisko.win
X-PowerMTA-VirtualMTA: mta-144.217.22.102
Received-From-MTA: dns;bwada3.xyz (144.217.22.102)
Arrival-Date: Fri, 7 Dec 2018 00:42:47 +0000

Final-Recipient: rfc822;zzzzzzzzzzzzzz@xtra.co.nz
Action: failed
Status: 5.7.1 (delivery not authorized)
Remote-MTA: dns;mx.xtra.co.nz (210.55.143.33)
Diagnostic-Code: smtp;554 5.7.1 Message rejected due to possible spam content
X-PowerMTA-BounceCategory: spam-related

Does this mean someone has my xtra email account settings like password? 

Or , is it just spam to confuse me?