StartPosition is a readonly value you can use to
manually access mailbox file in case you need it. Once you
Lock your
mailbox, wodMailbox will parse complete file and only
gather information about messages start positions, end
positions, and their sizes. This is enough for you to
access them and get general information, uses very low
amount of memory, and it's extremely fast.
Once you want to access specific message, wodMailbox
will use StartPosition and EndPosition
properties to locate message in mailbox and load it to
memory (when needed, and depending which part is
needed).
You can use StartPosition and EndPosition properties if you want
to externally access mailbox file. For example, you might split it
to separate message files easily just by having this information.
Or, you can easily 'inject' new message in mailbox file, etc.