Re: Make username optional in email addresses

Tim Wicinski <[email protected]> Wed, 22 Feb 2023 15:51:48 -0500
Newsgroups gmane.ietf.smtp
Message-ID <CADyWQ+FMF6aQk_7VEfpHrbJDaTR98atNydP+9DfHiZaB1VSKjQ@mail.gmail.com>
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Scott

I have some domains where I would not mind the *@example.com, but most of
them I have a curated list of addresses I want to receive mail to, and the
rest can go away.  I'm curious where folks think the usage level would be.

tim


On Wed, Feb 22, 2023 at 3:46 PM Scott Antipa <[email protected]> wrote:

> I was thinking this would be a single special email per domain, eg =E2=80=
=9C
> [email protected]=E2=80=9D or whatever. Does that address the scaling =
problem?
>
> On Fri, Feb 17, 2023 at 6:25 PM John C Klensin <[email protected]> wrote:
>
>>
>>
>> --On Friday, February 17, 2023 17:30 -0500 tjw ietf
>> <[email protected]> wrote:
>>
>> > Speaking as a simple dns person
>> >
>> > _role.example.com TXT [email protected]
>> >
>> > Is my fuel for the discussion
>>
>> Tim,
>>
>> There are at least three issues there (or with something similar
>> using SRV records).
>>
>> One, which may not apply to the smaller, more personal, domains
>> I think Scott is most concerned about, is that sometimes the
>> process of modifying a DNS record involves different people
>> and/or procedures than modifying an email delivery MTA.
>>
>> Second, it is typically going to means three DNS lookups to
>> identify an email address and where to send it, one for the
>> _role record as shown, one to get the MX record(s) for the
>> target domain, and, unless one gets lucky and the addresses of
>> the servers identified in the MX records show up as additional
>> information, a third (or more) to retrieve the addresses for
>> that server or servers.
>>
>> And third, as I think was mentioned in another context, every
>> time that someone has proposed something that might involve a
>> DNS entry per person rather than per host or pseudo-host, the
>> conclusion has been that it would not scale properly.  Now
>> Scott's situation may be a bit different because I think he is
>> thinking about one email address per domain (or, if there were,
>> using the terminology of my earlier note, an "owner" and an
>> "all" one, two).  That might therefore not trigger the scaling
>> problem.  But, still...
>>
>> Whether one did it with a special name and DNS entry or a "role"
>> email address, I think the problem is the same" either the user
>> or the originating MUA needs to understand the naming or RR
>> convention and how to use it.  Then, with Scott's proposal, the
>> delivery server and everything in between need to understand a
>> now-prohibited address and the delivery server needs to
>> understand what it means.  With my  "owner" suggestion, the
>> delivery server has to have an alias for the correct/target
>> address (not unlike the usual treatment for "Postmaster"); with
>> yours the address on the wire is actually the target address.
>>
>> And, Scott, please pay attention to Nathaniel's comment.  Many
>> of us who "own" dedicated domains of which we are the only
>> important user use a multitude of email addresses to organize
>> materials, set up special security mechanisms, and so on.   I
>> don't know about Nathaniel, but I use subaddress mechanisms and
>> probably use hundreds of different addresses.  Some get special
>> post-delivery routing, others don't, and the rules change
>> frequently (in my case, it is rare for a week to go by without
>> my making at least one internal or routing or classification
>> change).  For us, "[email protected]" or "[email protected]"
>> would be just one more of those specialized addresses to put in
>> the relevant tables, tables that we need to maintain anyway.
>> Keeping in mind that "@gmail" would almost certainly either have
>> to be rejected or treated as a synonym for something
>> Postmaster-like and that at least some of the cases of
>> @personaldomain.example would be used as Nathaniel and I use
>> them, it is not clear to me that there would actually be
>> significant demand for "@example.com" even if you could get it
>> adopted.
>>
>> best,
>>    john
>>
>>

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<div dir=3D"ltr"><div class=3D"gmail_default" style=3D"font-family:monospac=
e">Scott</div><div class=3D"gmail_default" style=3D"font-family:monospace">=
<br></div><div class=3D"gmail_default" style=3D"font-family:monospace">I ha=
ve some domains where I would not mind the *@<a href=3D"http://example.com"=
>example.com</a>, but most of them I have a curated list of addresses I wan=
t to receive mail to, and the rest can go away.=C2=A0 I&#39;m curious where=
 folks think the usage level would be.=C2=A0</div><div class=3D"gmail_defau=
lt" style=3D"font-family:monospace"><br></div><div class=3D"gmail_default" =
style=3D"font-family:monospace">tim</div><div class=3D"gmail_default" style=
=3D"font-family:monospace"><br></div></div><br><div class=3D"gmail_quote"><=
div dir=3D"ltr" class=3D"gmail_attr">On Wed, Feb 22, 2023 at 3:46 PM Scott =
Antipa &lt;<a href=3D"mailto:[email protected]">[email protected]</=
a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0p=
x 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><d=
iv dir=3D"auto">I was thinking this would be a single special email per dom=
ain, eg =E2=80=9C<a href=3D"mailto:[email protected]" target=3D"_blank">=
[email protected]</a>=E2=80=9D or whatever. Does that address the scalin=
g problem?</div><div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=
=3D"gmail_attr">On Fri, Feb 17, 2023 at 6:25 PM John C Klensin &lt;<a href=
=3D"mailto:[email protected]" target=3D"_blank">[email protected]</a>&gt; w=
rote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0p=
x 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br>
<br>
--On Friday, February 17, 2023 17:30 -0500 tjw ietf<br>
&lt;<a href=3D"mailto:[email protected]" target=3D"_blank">tjw.ietf@gmail.=
com</a>&gt; wrote:<br>
<br>
&gt; Speaking as a simple dns person<br>
&gt; <br>
&gt; _<a href=3D"http://role.example.com" rel=3D"noreferrer" target=3D"_bla=
nk">role.example.com</a> TXT <a href=3D"mailto:[email protected]" target=
=3D"_blank">[email protected]</a><br>
&gt; <br>
&gt; Is my fuel for the discussion <br>
<br>
Tim,<br>
<br>
There are at least three issues there (or with something similar<br>
using SRV records).=C2=A0 <br>
<br>
One, which may not apply to the smaller, more personal, domains<br>
I think Scott is most concerned about, is that sometimes the<br>
process of modifying a DNS record involves different people<br>
and/or procedures than modifying an email delivery MTA.=C2=A0 <br>
<br>
Second, it is typically going to means three DNS lookups to<br>
identify an email address and where to send it, one for the<br>
_role record as shown, one to get the MX record(s) for the<br>
target domain, and, unless one gets lucky and the addresses of<br>
the servers identified in the MX records show up as additional<br>
information, a third (or more) to retrieve the addresses for<br>
that server or servers.<br>
<br>
And third, as I think was mentioned in another context, every<br>
time that someone has proposed something that might involve a<br>
DNS entry per person rather than per host or pseudo-host, the<br>
conclusion has been that it would not scale properly.=C2=A0 Now<br>
Scott&#39;s situation may be a bit different because I think he is<br>
thinking about one email address per domain (or, if there were,<br>
using the terminology of my earlier note, an &quot;owner&quot; and an<br>
&quot;all&quot; one, two).=C2=A0 That might therefore not trigger the scali=
ng<br>
problem.=C2=A0 But, still...<br>
<br>
Whether one did it with a special name and DNS entry or a &quot;role&quot;<=
br>
email address, I think the problem is the same&quot; either the user<br>
or the originating MUA needs to understand the naming or RR<br>
convention and how to use it.=C2=A0 Then, with Scott&#39;s proposal, the<br=
>
delivery server and everything in between need to understand a<br>
now-prohibited address and the delivery server needs to<br>
understand what it means.=C2=A0 With my=C2=A0 &quot;owner&quot; suggestion,=
 the<br>
delivery server has to have an alias for the correct/target<br>
address (not unlike the usual treatment for &quot;Postmaster&quot;); with<b=
r>
yours the address on the wire is actually the target address.<br>
<br>
And, Scott, please pay attention to Nathaniel&#39;s comment.=C2=A0 Many<br>
of us who &quot;own&quot; dedicated domains of which we are the only<br>
important user use a multitude of email addresses to organize<br>
materials, set up special security mechanisms, and so on.=C2=A0 =C2=A0I<br>
don&#39;t know about Nathaniel, but I use subaddress mechanisms and<br>
probably use hundreds of different addresses.=C2=A0 Some get special<br>
post-delivery routing, others don&#39;t, and the rules change<br>
frequently (in my case, it is rare for a week to go by without<br>
my making at least one internal or routing or classification<br>
change).=C2=A0 For us, &quot;<a href=3D"mailto:[email protected]" target=3D=
"_blank">[email protected]</a>&quot; or &quot;<a href=3D"mailto:everyone@ex=
ample.com" target=3D"_blank">[email protected]</a>&quot;<br>
would be just one more of those specialized addresses to put in<br>
the relevant tables, tables that we need to maintain anyway.<br>
Keeping in mind that &quot;@gmail&quot; would almost certainly either have<=
br>
to be rejected or treated as a synonym for something<br>
Postmaster-like and that at least some of the cases of<br>
@personaldomain.example would be used as Nathaniel and I use<br>
them, it is not clear to me that there would actually be<br>
significant demand for &quot;@<a href=3D"http://example.com" rel=3D"norefer=
rer" target=3D"_blank">example.com</a>&quot; even if you could get it<br>
adopted.<br>
<br>
best,<br>
=C2=A0 =C2=A0john<br>
<br>
</blockquote></div></div>
</blockquote></div>

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