Email from ZBD, how is having a dormant account a security threat? If you want to weed out inactive accounts, just say use it or lose it. But, "security threat?", come on.
https://files.peakd.com/file/peakd-hive/crrdlx/23vsn7S5hKtoFmsRjr1zoMYTbmiwQq1NBedmsqD5sjMF9zXaDqYK9Zo3qHj4Zg87f9EfZ.png)