how do you find the mailbox store defaults in exchange 2003

Could you be more specific on what it is you need as the "defaults" are all over the Exchange Management console really.

Size Limits for sending and recieving:

Global Settings –> Message Delivery –> right click Properties  and select the Defaults register

Database store size:
http://www.petri.co.il/change_store_size_limits_ex2003_sp2.htm

strat up Exchange System Manager
see attached image
Untitled-3.jpg

I think Yukovarcan is what I want.  But when I go to that page those limits are greyed out.  I assume they are the default limits for the size of mailboxes.  But if they are greyed out where is the setting that presumedly overides them and sets new limits?

Greyed out means that they are set to the numbers that are currently greyed out.
To enable different defaults, tick the boxes beside the numbers and the greyed out boxes will no longer be greyed out.  Then enter a larger number up to the maximum (you will be advised what that is if you exceed it).

Sorry what I mean is the entire tab is greyed out.  I cant untick the boxes because the checkboxes themselves are greyed out.  What over rules them?