Bytes is a readonly property that gives you total number
of bytes in the message. This includes headers, text and
any additional parts of the message. It is retrieved while
looping through mailbox file when you called Lock method.
In most cases it will be same as Size property.
However, if message is poorly formatted, this can be quite
a different than Size. For instance, if original message
contains only linefeed, Size might be smaller because when
loaded to memory, wodMailbox would replace these with CRLF
sequences - thus needing one more byte for each new
line.