But the MX servers which KNOW active accounts end up being used in
mail-harvesting for spammers to begin with.  If you get a blank mail or
sometimes with garbage apparently from nowhere real this is much more likley
to be someone harvesting your mail server or cleaning up their spam-lists of
dead accounts then a trojan...

> -----Original Message-----
> From: LISTSERV site administrators' forum 
> [mailto:[log in to unmask]] On Behalf Of Patrick 
> von der Hagen
> Sent: Monday, August 01, 2005 1:12 PM
> To: [log in to unmask]
> Subject: Re: Spamcop problems
> 
> Am Freitag, den 29.07.2005, 17:21 +0200 schrieb Eric Thomas:
> [...]
> > perfectly good reasons? That MX server does not know what 
> addresses exist at
> > the other server and cannot answer in-line. Either way, the 
> only difference
> There are many, many ways how a MX-server can know what 
> addresses exist
> at the servers it is responsible for. If you are not able to install a
> MX-server that does only accept valid addresses, you should 
> not operate
> an MX-server at all.
> 
> However, even if you MX-server has the information, which 
> addresses are
> basically valid, legitimate bounces can be created. For example, the
> address is valid, but over mail-quota. Or the address is forwarding to
> some other address, wich is unreachable, disabled, over quota, etc.
> 
> --
> CU,
>    Patrick.
>