To reduce memory requirements with large mailboxes,
wodMailbox does not load them messages in memory
immediately when you Lock mailbox file. Rather, it always
tries to get references to positions in mailbox
that might be needed later. This results in
extremely fast mail parsing, and does not allocate memory
at all.
However, when you actually need some message, it is
internally loaded into the memory for you when you access
it. You can do this manually using Load method, or just
let wodMailbox do this for you when needed.
When you have several large email messages in the
mailbox, you might want to consider that after evaluating
and using one message, you could Unload it from memory, and
switch to some other message. In such cases, you will call
this method. When you need the same message next time,
wodMailbox will have to Load it again.