OT: Spam Problems

[Heinz Diehl]

On 09.07.2012, Errol Mangwiro  wrote: 

> Recently I started receiving bounces from mail purporting to having
> been sent from addresses in my domain. But the addresses don't
> exist. So I thought that someone was faking the sender header and
> sending spam.

Please post the _full_ header of such a mail.

> I added SPF and domain-key records to try to combat this. 
> However, either hotmail and yahoo don't check these or they 
> ignore them because I'm still getting spammed. 

It's trivial to fake any From: header, and there's nothing you can do
about that, unfortunately. 
 
> Does anyone know of a way I can tighten fake sender policies & prevent this from occuring again?

You can't prevent people from faking the From: header. Any spamfilter
or network admin who tags email as spam according to From: is a moron.

The correct way is to see if all these spam-emails originate from the
same server, and send the admin an epost. To do this, a look at the
complete and original header of one of those spammails is neccessary.