|Subject:||[courier-users] Re: 'sender' and 'receiver' attributes in Received-SPF?|
|From:||Lloyd Zusman (lj...@asfast.com)|
|Date:||Aug 31, 2004 5:42:08 pm|
Sam Varshavchik <mrs...@courier-mta.com> writes:
Lloyd Zusman writes:
I want to make sure that I understand how the 'sender' and 'receiver' attributes get set within the three kinds of Received-SPF headers that Courier can generate. Is the following information correct? HELO Received-SPF sender: value of helo/ehlo field receiver: hostname of machine on which Courier is running MAILFROM Received-SPF sender: envelope sender (SMTP "mail from:" value) receiver: hostname of machine on which Courier is running FROM Received-SPF sender: value of "From:" email header receiver: hostname of machine on which Courier is running If so, I take it that the 'receiver' attribute will always be set to the same value on a given host, no matter which Received-SPF header it appears in, and no matter which SPF-related conditions might be in effect. Correct?
Yes; however note that Courier will leave any existing Received-SPF: headers, perhaps inserted by the previous mail relay, untouched (except that they will be moved to the end of the existing headers, so that Courier's headers always come first). And, the previous relay can easily be configured to use the same hostname.
So how can I know for sure which of the Received-SPF headers were inserted by my Courier instance, and which were hanging around from before? The number of Received-SPF headers that Courier writes is variable, and furthermore, it depends on the settings in my 'bofh' file at the moment that the email is going through my system ... which could change by the time any given message is being handled by my own filters.
Is there some deterministic way for us to always know exactly how many Received-SPF headers that Courier writes into a given message?
If not, how about putting the count of Courier-written Received-SPF headers into the topmost Received header that Courier writes? It would then be irrefutably accurate.
Or if that's not possible, could the older Received-SPF headers be changed to X-Received-SPF headers?
Or how about putting one more place-holding header into the message, right after the final Received-SPF header and before any others that other hosts might have written ... maybe something like X-Courier-SPF-Info which contains some sort of summary of Courier's SPF processing. Upon encountering this header, we could be sure that there are no more Courier-inserted Received-SPF headers to process.
-- Lloyd Zusman lj...@asfast.com God bless you.