2.2.20 [RFC3501] Section 6.3.9, LSUB Command
The specification prescribes rules that apply to mailbox names that are returned in the LSUB response.
Microsoft Exchange Server 2007
If a mailbox name contains the backslash character ("\"), then Microsoft Exchange Server returns the mailbox name as a literal preceded by a <length> field.
Microsoft Exchange Server 2010, Microsoft Exchange Server 2013, Microsoft Exchange Server 2016
If a mailbox name contains the backslash character ("\") or the double-quote character ("""), then Microsoft Exchange returns the mailbox name as a literal preceded by a <length> field.
The specification states: "The returned untagged LSUB response MAY contain different mailbox flags from a LIST untagged response."
Exchange 2007, Exchange 2010, Exchange 2013, Exchange 2016
Microsoft Exchange supports an untagged LSUB response containing mailbox flags that are different from those in an untagged LIST response. The flags differ according to the mailbox's existing flags.