Re: [exim-dev] mx points to self - good

On Fri, Oct 25, 2013 at 6:36 AM, Viktor Dukhovni
<viktor1dane@???> wrote:
>> On 25/10/13 14:15, Jasen Betts wrote:
>> >The domain names will all be CNAME to a known domain name and the MX
>> >on that domain points
> However accepting mail for all domain names aliased to a given name
> or resolving to a given IP address is not necessarily wise.
> Anyone can create an alias, or point their domain's MX records at
> the IP address in question. It is generally better to accept mail
> only for an explicitly configured list of domains.

For a short while back in the early 2000's, a sendmail rpm had a
feature enabled where if the MX pointed to your mail server, sendmail
interpreted that as "you must want me to relay mail for this domain."
It didn't take long before spammers started pointing their domain's
MX's to thusly configured servers and blasting out spam. It didn't
take long for that feature to get changed back to off.

...Todd
--
The total budget at all receivers for solving senders' problems is $0.
If you want them to accept your mail and manage it the way you want,
send it the way the spec says to. --John Levine