>> Is this a true statement. If a message is sent to postfix via smtp, in the
>> message headers will ALWAYS be at least one header of the form:
>>
>> Received: from...
>>
>> I believe this to be the case, which means the only messages without that
>> are the locally sent emails. Wouldn't that be true?
>Yes, this is generally true. If you're using a
>content_filter, it may add headers too.
Then, this solves my problem. I don't care if there are 5 of them, if there are
none, and of course assuming one did not filter them out somehow, then, it's
local mail which is exactly what I needed to determine.
