Subject: Re: Sendmail and anti-spam
To: Andrew Brown <twofsonet@graffiti.com>
From: Bill Studenmund <wrstuden@nas.nasa.gov>
List: tech-userlevel
Date: 02/18/1999 12:50:35
On Wed, 17 Feb 1999, Andrew Brown wrote:

> >} We should perhaps deny relaying and perhaps also accepting mail from
> >} hosts that have no valid mx or such.
> >
> >     Absolutely NOT, this is completely bogus.  MX records indicate
> >machines that are intended to receive mail, NOT one's that are
> >intended to send mail.
> 
> a generic bsd4.4 config file from sendmail 8.9.3 will not openly relay
> mail from anyone.  indeed, it will only accept mail that originates or
> terminates locally (modulo any local forwarding rules of course).
> 
> it will also not accept mail from an invalid sender address, ie, the
> domain portion after the @ must either have an mx record or an a
> record associated with it.

I think the sharp emotions stem from the fact that some sites don't add
the "or an a record" bit, and require mx records. Rather broken. I think
requiring an a or an mx is fine. :-)

Take care,

Bill