"Between September 2012 and late 2014, the emails were sent to around a dozen people, including very senior academics and officials within the University of Sydney."

Perhaps one of these recipients passed on their copy to NM?

"A source within the University of Sydney, connected to the School of Letters, Art and Media (SLAM) - which includes the English Department - has confirmed that the emails were sent from Professor Spurr’s official university email address."

That doesn't mean his email account (WORK) was hacked.