Slight nitpick: it's not clear that this particular email was about a workplace relationship (or sent on company time/servers). It was an email included as evidence in a civil suit by his ex-wife:
> In a civil suit filed this month by Mr. Rubin’s ex-wife, Rie Rubin, she claimed he had multiple “ownership relationships” with other women during their marriage, paying hundreds of thousands of dollars to them. The couple were divorced in August. The suit included a screenshot of an August 2015 email...
The email was from 2015, but he had left Google in 2014, so it wasn't sent on company time/servers.
Even if it had been sent earlier, Andy Rubin had been named in enough patent lawsuits and deposed enough times to know that multiple plaintiffs had lawyers billing $700/800 per hour (at the very least) to go through all his corporate account's messages. He must have had tens of litigation holds.
> In a civil suit filed this month by Mr. Rubin’s ex-wife, Rie Rubin, she claimed he had multiple “ownership relationships” with other women during their marriage, paying hundreds of thousands of dollars to them. The couple were divorced in August. The suit included a screenshot of an August 2015 email...