[Mimedefang] Adding filter_helo support

[David F. Skoll]

Philip Prindeville wrote:

> It was previously passed in filter_sender() because it wasn't
> available earlier (since obviously there was no support for
> "helos"). This was a design short-coming. And it's an attempt to
> KISS, by dividing and conquering the problem...

But it breaks existing filters; we need the helo arg back.
And there's a good reason to pass HELO in filter_sender (and
filter_recipient, for that matter): You may WANT to defer your
HELO processing until later.  Our commercial products, for
example, let individual recipients decide if they want to use
various rules, which means we need to defer all processing
until at least RCPT.

> In any case, the variable continues to be present in $Helo.

Not in filter_sender if we use your patch, unless we parse the
commands file manually.

If you re-work your patch to leave filter_sender as it was, I will
include it in the official release.

Regards,

David.