Ruleset questions

[Richard Frovarp]

Glenn Steen wrote:
> 2008/8/14 Richard Frovarp <Richard.Frovarp at sendit.nodak.edu>:
>   
>> How would one go about blacklisting a From email address that is did not
>> come from a subnet. Email would for this one address would only come
>> legitimately from one of my subnets. Everything else should be thrown away.
>> What would be the best way to accomplish this?
>>
>> Thanks,
>> Richard
>>     
> Apart from SPF, which I'm sure one could use to reject fakers, one
> could do as I do in postfix... I simply reject all faked senders (we
> only allow internal senders for our domain, exactly as you would
> likedo it)... A simple access map restriction on the sender...
> something like "smtpd_sender_restrictions
> permit_mynetworks,check_access regexp:/path/to/accessfile ... How one
> would do it with other MTAs... I do not know... Should be possible
> though:-).
>
> Cheers
>   

SPF wouldn't do it. SPF would only check the envelope from. We are 
concerned about the displayed from. And in particular of only one of our 
accounts.

We run sendmail. However, how does your system handle mail from other 
systems claiming to be from your users? Like say this mailing list?

Richard