GetCurrentUserMailboxSize()
From Rackspace Email & Apps API
This function will report the amount of space used in a given mailbox. This information is updated nightly. Size is given in megabytes.
Input Parameters
Four strings, one result integer:
Administrative username, Administrative password, Domain name, User name,
Size in MB
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.