Vista - Offline Messages / Live Messenger for Blackberry

I have two quick questions:

1) How long are offline messages typically stored and is there a limit to
how many are saved for delivery to the recipient? Yes, I know the typical
response to questions with regards to Offline messages is just send an email.
Unfortunately the particular person that I am sending offline messages to
rarely checks email and is online more than they check their email, so
offline messages is the only alternative for the moment.

2) With the current version of Live Messenger supporting multiple log ins,
will there eventually be support for this feature for Live Messenger for the
Blackberry? I do check from time to time to see if there has been a newer
version released or any mention of support for this but have not seen or
found anything reference to this.

Thank You!