I knew that guy who auto-forwarded personal mail to his work mail. Then once he went on leave he setup an auto-forward from his work email to his personal email

I knew that guy who auto-forwarded personal mail to his work mail. Then once he went on leave he setup an auto-forward from his work email to his personal email. Problem was he forgot to turn-off his private email forwarded and created a fine infinite loop of forwards that effectively crashed the email server.