CheckAliasExists()
From Rackspace Email & Apps API
This function will report if an alias exists that exactly matches the string passed by the function.
Input Parameters
Four strings:
Administrative username, Administrative password, Domain name, Search string (may be partial alias name)
Return Values
If successful, the return value of the function will be 1 if the alias exists in the system, 0 for doesn't exist.
Consult the Result Code Table for a list of result codes and their meaning.