I found the Mail Deliver Subsytem notification (see below) in my Gmail inbox this morning. Has my account been hacked?

The message says an email from my account could not be delivered because the destination address was incorrect. The email message that bounced was in Italian and looks like spam (based on my limited Italian). I never sent the message and I don't write enough Italian to be able to spam anyone in that language.

I only access this Gmail account with a browser from (1) my Ubuntu 14.04 machine or with the Gmail app on my Android phone and tablet. Any suggestions on how to find any malware on my Ubuntu machine or my Android machines that could have sent this message?

Thanks!

Mark
==============================================================
The suspicious message:

Phillips Marketing, Inc. Mail    Mark Phillips <mark@phillipsmarketing.biz>
Delivery Status Notification (Failure)
Mail Delivery Subsystem <mailer-daemon@googlemail.com>    Sun, Jan 29, 2017 at 12:51 AM
To: mark@phillipsmarketing.biz
Error Icon
Address not found
Your message wasn't delivered to hlrecherche@auchan.it because the address couldn't be found. Check for typos or unnecessary spaces and try again.

Final-Recipient: rfc822; hlrecherche@auchan.it
Action: failed
Status: 5.0.0
Last-Attempt-Date: Sat, 28 Jan 2017 23:51:21 -0800 (PST)


---------- Forwarded message ----------
From: <mark@phillipsmarketing.biz>
To: <hlrecherche@auchan.it>
Cc:
Date: 29 Jan 2017 13:16:17 +0200
Subject: Guadagni extra per voi! 700-1000 euros alla settimana.
Caro hlrecherche,

Io sono HR manager di una grande compagnia internazionale.
La nostra azienda &#232; alla ricerca di collaboratori intraprendenti.

Il stipendio possibile da 2500 a 5000 euro al mese.

Se Le interessa nostra offerta - si prega di visitare il
Nostro Sito

Con i migliori saluti,
HR Manager
Ufficio Internazionale