OT: Sendmail REJECT or DISCARD preference

[Matt Kettler]

Peter Farrow wrote:
> Matt Kettler wrote:
>> Peter Farrow wrote:
>>> Matt Kettler wrote:
>>>> Peter Farrow wrote:
>>>>
>>>>>> Steve.
>>>>> If you reject,  and its spoofed you'll get it back anyway, so you 
>>>>> end up receiving and then storing it in the postmaster address, it 
>>>>> is always best to discard in this scenario...or even worse bouncing 
>>>>> it again
>>>>>
>>>>
>>>> Stop confusing REJECT with post delivery bouncing :) See my other 
>>>> post in this thread.
>>> I am talking about sendmail access file entries at the MTA level.... 
>>> nothing else...my point is the general notice supplied in the REJECT 
>>> directive often ends up coming back round...I've seen it many times..
>>
>> That's exactly what I'm talking about. I've got several such entries, 
>> and I've never seen any of them come back. ever.
>>
>> There's something seriously wrong with your mailserver if this is 
>> happening.
> This is how it works:
> 
> Someone sends a spoofed spam email to one of my clients the other side 
> of my mailscanner, but they get the address wrong.
> 
> The mailer daemon on the client server rejects the email, (I am the 
> postmaster for my clients Linux server) with user unknown,


Well, duh. That's because the REJECT isn't being implemented at the MX, but a 
downstream server.

In order to avoid the postmaster issue you *MUST* implement this at all of the 
MXes for the domain.

Of course it will cause the problem if a downstream server does a REJECT, 
because it's being REJECTED after your server accepted it.

However, this doesn't make REJECT bad, it just means the REJECT needs to be 
implemented on YOUR server, not your clients.