I worked for a conglomerate a few years ago but had a simple email. I realized my email was recycled after I started receiving all kinds of unusual emails... like emails for an old personal eBay account. It was funny at first, but it was definitely a security liability for himself and the company as I was occasionally sent emails I'm sure I should not have been included on (he was a higher level, and was part of several mailing lists that were not purged after he left).