Property Value

Type: Int64
The non-negative Int64 value containing the storage limit (in bytes) for the account or folder the quota applies to, or -1 if this information is not available.

This value, if non-negative, is a multiple of 1024 (this is because the mail server actually returns this value in kilobytes). Thus, the developer can divide it by 1024 to get the value returned by the server.