Alias.__init__(): Check really if the given address is not used.
# All parameters are described in pgsql_table(5) / PGSQL PARAMETERS## The hosts that Postfix will try to connect to and query from.hosts=localhost# The user name and password to log into the pgsql server.user=postfixpassword=some_password# The database name on the servers.dbname=mailsys# The SQL query template used to search the databasequery=SELECTuidFROMpostfix_uidWHEREaddress='%s'