poison mailbox

A Poison Mailbox is a corrupted mailbox of an Exchange Server that causes disruptions in the Exchange database store.

Such a tainted mailbox can cause faulty functionality or prevent access to all mailboxes hosted by the Exchange Server. Exchange Servers 2010 and later can block Poison Maiboxes before they disrupt the Exchange database store and affect messaging platforms. They lock infected mailboxes and disconnect them from users or other processes.