[Mimedefang] Per-recipient customization

[Matthew.van.Eerde at hbinc.com]

David Eisner wrote:
> Whether or not you think it's a good idea, I need to give users the
> option of discarding messages with SpamAssassin scores above a certain
> threshold.  Such messages should be discarded at the server running
> MIMEDefang, before they reach the user's MUA.  Right now we tag them
> with the X-Spam-Score header in the usual way.
> 
> What would be a good way to approach this?  The first thing that comes
> to mind is putting the file in /etc/mail/ (say
> /etc/mail/mimedefang_user_prefs.cf), read it in filter_initialize(),
> and then use it in filter_end() somewhere after spam_assassin_check().

Sounds reasonable.
 
> Another issue: how to handle one message with multiple envelope
> recipients, not all of whom have the same policy. I need to RTFM and
> think about this a bit more, but would it be relatively easy to strip
> some recipients in filter_end(), and leave others, before the message
> is forwarded through the mailertable mechanism?

Yup... see action_delete_recipient

You have three eventualities:

* None of the message's recipients are deleted
* Some but not all of the message's recipients are deleted
* All of the message's recipients are deleted

The first case is the "normal" case... no special action required.
The third case is easy... action_bounce (actually does a "reject", not a bounce)
The second case has me on tenterhooks.  You CAN do it your way (action_delete_recipient), but why not greylist, and if it comes back, accept?

-- 
Matthew.van.Eerde (at) hbinc.com               805.964.4554 x902
Hispanic Business Inc./HireDiversity.com       Software Engineer