[Mimedefang] MX -> 127.0.0.1

[Kevin A. McGrail]

Joseph Brennan was kind enough to share more code snippets with me which had 
predisposed me against a bounce.  BUT Joseph's code was originally done in 
filter_begin which led to my initial worry about reject/bounce vs discard.

However, right now, I am thinking I should be able to do the invalid helo 
and invalid MX check in filter_sender since I have $sender and that's all I 
need.  If I reject in filter_sender, I haven't received the entire email yet 
and it isn't a very "costly" transaction.

Regards,
KAM


> Regardless of how you feel about bounce vs drop on spams, this might be
> one where rejecting should be done.  This will notify the sending site
> that they have hosed DNS entries.  Including a link to a page with
> explanation on why their DNS is fubar would be good. (That assumes the
> sending host includes the rejection notice.  I've been asked to diagnose
> messages that only say that the delivery failed and do not include any
> details.  Useless!)