AW: [Mimedefang] Detect mail loops in mimedefang ?

[Joseph Brennan]

--On Thursday, July 28, 2005 15:54 +0200 Florian Meister 
<Florian.Meister at medienhaus.at> wrote:

> Imagine the following:
>
> 2 mail relays and one mail-storage. The mail-storage has a webinterface
> on which you can redirect your mail. You redirect the mail to a mailbox
> which does not exist, and because of the redirect the Return-Path points
> to the redirected mailbox. The Server to which is redirected sends a
> bounce-mail. The bounce-mail comes in to the mail-relays. The mail relays
> do not see that the mail is rotating, because of the forwarding. Then the
> mail is forwarded and bounced again and gets bigger and bigger.


I might be reading this wrong, but it looks like the "redirect"
sends with the local user as the sender, instead of the original
sender.  This is the problem.  The bounce cannot get back to the
real sender.  A traditional forward does not change the sender
address.

You could mark redirected mail with a X-header, and check header
and body of incoming for that X-header.  But what would you do
when you find it?  Force local delivery?  Then your user never
sees it.  Throw it away?  Then the original sender does not get
notified.

So I think the solution is not to send the redirected mail with
the local user as the sender address.

Joseph Brennan
Academic Technologies Group, Academic Information Systems (AcIS)
Columbia University in the City of New York