Proper Way to Configure a Domain which never sends emails

[Ignacio García]

Hi there.

Thanks for your support. First message to the list, sorry if already 
posted a similar question, but I haven't found mention anywhere.

I have to set up dns records for a domain just for a web site, for which 
we will NEVER send emails (though we might receive some from old 
customers), so I would like to announce somehow that emails sent from 
this domain should always be disregarded. I was thinking of setting just 
A and AAAA records for @ and www, NS records, MA records (for receiving) 
and SPF with a record just consisting of v=spf1 -all  , not declaring an 
A and MX records at all. I'm not sure at all this is a proper way of 
declaring this. In fact, what I would like is to EXPLICITELY mention 
somehow that we will never send emails from that domain. Could anybody 
help me with this?

Thanks so much in advance.

Ignacio