BertjanBroeksema &tde-authors; &tde-release-version; Reviewed: &tde-release-date; 2010 Bertjan Broeksema &tde-copyright-date; &tde-team; This handbook describes the mbox protocol. TDE mbox protocol The mbox file format is an simple but rather inefficient way to store email messages. All messages are appended after each other in the same file separated by a special separator line. This gets especially expensive when you have many emails in the same file.