Path: ...!weretis.net!feeder9.news.weretis.net!news.misty.com!news.iecc.com!.POSTED.news.iecc.com!not-for-mail
From: John Levine <johnl@taugh.com>
Newsgroups: comp.mail.misc
Subject: Re: mail @example.com without dns a-record for example.com
Date: Sun, 22 Dec 2024 21:00:05 -0000 (UTC)
Organization: Taughannock Networks
Message-ID: <vk9ukl$20ni$1@gal.iecc.com>
References: <878qs7wvmy.fsf@example.com>
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In-Reply-To: <878qs7wvmy.fsf@example.com>
Cleverness: some
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Originator: johnl@iecc.com (John Levine)
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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?


-- 
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly