Item property will return specific message from
collection of all messages, or will return specific part of
the message from the message, depending when is used.
For example,
mailbox.Messages.Item(3) would
return 4th message in the mailbox,
and
mailbox.Messages.Item(3).Parts.Item(2) would
return 3rd part of the message, to be more precise 4th
message.
Usually you don't have to write Item because
it's default property. It's easier to use
mailbox.Messages(3) instead of
mailbox.Messages.Item(3).