Re: mail @example.com without dns a-record for example.com

If you want help, you need to tell us the actual domain.  Otherwise we'd
just be guessing what you did.

According to Salvador Mirzo  <smirzo@example.com>:

Followup-To: comp.mail.misc
>
The objective here is just learning how things work.  I asked
myself---is it possible to get mail sent to someone@example.com without
an a-record fore example.com?  I think the answer should be ``yes''
because I thought an SMTP would do a type-mx dns query, learn that
example.com mail is handled by mx.example.com, would get the ip address
of mx.example.com and reach the server just fine.
>
So I made an experiment using my domain---example.com, say.  I've been
geting mail just fine every day.  Then I deleted the a-record for
example.com.  My mail system is not really dependent on it in any way as
far as I know.  So the experiment has the set up:
>
# host -t a example.com
example.com has no A record
>
# host -t mx example.com
example.com mail is handled by 10 mx.example.com.
>
# host -t a mx.example.com
mx.example.com has address 1.2.3.4
>
But after the deletion of the a-record example.com, I noticed Gmail
seems not to deliver emails to me anymore.  As soon as I created it back
and send a new message, it arrived just fine.
>
Is is just Gmail or is there more I don't understand?

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