11e51f25_muniGate_Pro_Server__Mailboxes__Negative_Name
[Name] Service [Description] Messages with this flag set are not visible to IMAP or POP clients. MAPI clients can use this flag to create service items invisible to users (such as Mailbox forms). [IMAP Name] $Service [Negative Name] 
NotService
CommuniGate Pro Server: Mailboxes
Negative Name