2.2.11 [RFC3501] Section 3.4, Logout State


The specification states: "A client SHOULD NOT unilaterally close the connection, and instead SHOULD issue a LOGOUT command."

Microsoft Office Outlook 2007, Microsoft Outlook 2010, Microsoft Outlook 2013, Microsoft Outlook 2016, Microsoft Outlook 2019

Under certain error conditions, Outlook drops the connection without sending a LOGOUT command.