The MailboxPath property returns the current mailbox
reference path. If no path has been specified by the client, this
property will return an empty string.
Setting the MailboxPath property will determine which
mailboxes are returned by the Mailbox property array.
Typically this is used to specify a subdirectory where mail folders
are stored for the current user. Note that some mail servers may not
permit absolute reference paths, and in most cases the path should
include a trailing slash. This property may be used in conjunction
with the MailboxMask property to further qualify which
mailboxes are returned.