Am 10.11.2017 um 15:59 schrieb Александр Кириллов via Exim-users: > I'm trying to reduce backscatter which is a side effect of incoming spam.
> If you know of any other politically correct ways of solving this please
> share your experience. TIA.
Very likely discarding messages is not what you should do in this situation.
Rejecting spam during the SMTP dialog is good because the sender gets
immediate feedback.
For example this can be helpful for bigger providers who may monitor their
outgoing connections and lock accounts if too many messages are rejected. Also
legitimate senders don't have to worry about opaque "inboxing" rates.
More to the point "backscatter" is a rejection AFTER the SMTP dialog. This
mostly happens if you have multiple servers in a cascade and one machine
starts rejecting spam. This should be avoided because the previous MTA creates
a bounce message to the "sender" address which might be faked.
If you try to prevent backscatter configure your servers so that only the
first one does any rejections. If you just reject spam messages when getting
them the first time there is no "backscatter" problem.
If you can not control/reconfigure the first machine you must deal with "spam
folders".
Personally I'd *strongly* advise against discarding messages (and if you
really need it you don't need to read my post).
Felix
