GetUserMailboxMaxSize()
From Rackspace Email & Apps API
This function will report the max size of a particular mailbox (taking into account any extra allocated storage on the mailbox).
Input Parameters
Four strings, one result integer:
Administrative username, Administrative password, Domain name, User name,
Max mailbox size (int, MB of max storage space that may be used by the mailbox)
Return Values
If successful, the return value of the function will be 1.
Consult the Result Code Table for a list of result codes and their meaning.
