def authority_explanation
if self.instance_variable_defined?(:@authority_explanation)
return @authority_explanation
end
@authority_explanation = nil
server = @server
request = @request
authority_explanation_macrostring = request.state('authority_explanation')
if authority_explanation_macrostring
begin
@authority_explanation = authority_explanation_macrostring.expand
rescue SPF::InvalidMacroString
end
end
unless @authority_explanation
@authority_explanation = server.default_authority_explanation.new({:request => request}).expand
end
return @authority_explanation
end