Exchange 2010 UM auto attendant does not answer

if you have issue with newly created AA and you have eventlog entry with ID 1021(The Unified Messaging server rejected an incoming call with the ID <>. Reason: "The Unified Messaging server can’t find a valid UM hunt group for <> associated with UM IP gateway"), then make sure you have created an account with no spaces in the name. Otherwise delete and create new AA.