I was lightly probing this function's behavoir. It handles rfc882 fields:datesubjectmessage_idtofromreply-tosender - will generate using 'from' field if not in headerreferencesin-reply-toccdoesn't handle rfc882 fields:return-path receivedresent- I think this field may be obsoletekeywords If there are other rfc822 fields or behavoirs for the function, then I can't speak of them as they weren't in my test.As it is relevent to what I'm currently doing I may add more about this function from time to time.