listreceivedbyaccount [minconf=1] [includeempty=false]
[minconf] is the minimum number of confirmations before payments are included.
[includeempty] whether to include accounts that haven't received any payments.
Returns an array of objects containing:
"account" : the account of the receiving addresses
"amount" : total amount received by addresses with this account
"confirmations" : number of confirmations of the most recent transaction included