Re: [exim] Pre-emptive fallback hosts ?

From: "Jerry Nicholls" <Jerry.Nicholls@???>
>
> On Tue, 2004-09-14 at 12:34, Chris Edwards wrote:
>
> > First of all you'll need a way to flag when too many emails fail or
defer.
> > I'd be inclined to use a log-watcher script, but no idea if that's
> > practical in your environment. Whatever, I guess you'll end up with
a
> > table of maybe-compromised customer IP addresses.
>
> I'd prefer not to have any external process with this. I already do a
> 'reverse' grey list on senders, ie if they send to too many recipients
> too fast they get 4xx errors on subsequent RCPTs until a timeout
occurs.
> All that's done with a MySQL database and ACL logic. I was hoping I
> could do the same for this instance. I can't currently figure out how
to
> update the database when a router has deferred or failed tho'.

How about using an expansion in a message condition in the ACL to look at
the text in $acl_verify_message and doing the update to your database
there? You could make the expansion a "noop" as far as the actual text is
concerned:

require
message = $acl_verify_message${if
match{$acl_verify_message}{defer}{${lookup mysql{insert into ...}{}{}}{}}
verify = recipient

It's a little hackish, but not more so than a log-watcher script, in my
opinion.

Just an idea. It's untested, so there may be {} or other errors in the
example above. You would need to tune the text match to whatever defer
reason you were interested in, the above is just an example.

David