Re: Re: Exim 4.41 + Exiscan 4.41-24 + libspf2 1.0.4

Scott Amory <[email protected]> wrote:
> I just noticed this the other day too.  So I dug around in the Exiscan
> patch and in the libspf2 library to find out why.  It appears that
> Exiscan waits for the HELO/EHLO to send its spf_init call which sets
> up stuff so that it can run the SPF check.  Part of the reason for
> this I would imagine is that spf_init calls SPF_set_helo_dom.  The
> spf library uses the HELO/EHLO domain as a backup if it can't find
> one in the MAIL FROM.  So it's not really required but for some
> reason Exiscan makes it required.  To see If I could get the SPF
> check to work without a HELO/EHLO I patched the Exiscan patch with
> some changes and it seemed to work, though I haven't done extensive
> testing on it yet.  Now Exiscan will perform on an SPF check (that
> should work) even when it doesn't get a HELO/EHLO.  Can anyone see a
> reason why this would be a bad idea?

Yes. The HELO/EHLO name is a *required* input to the SPF algorithm, and is
used in the case of null senders. I suppose Exiscan could assume some
pre-determined result if it doesn't have all the required values, but it
wouldn't be following SPF properly.

Peter