Re: [ietf-smtp] SMTP client certs
"John Levine" <johnl@taugh.com> Wed, 01 January 2020 18:34 UTC
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Date: Wed, 01 Jan 2020 13:34:27 -0500
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From: John Levine <johnl@taugh.com>
To: ietf-smtp@ietf.org
Cc: moore@network-heretics.com
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Archived-At: <https://mailarchive.ietf.org/arch/msg/ietf-smtp/Doy5K06zy30hJsO1Z7RYoj3JqHI>
Subject: Re: [ietf-smtp] SMTP client certs
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In article <8820eca1-c17d-0821-5fe4-8a46c22a3e7b@network-heretics.com> you write: >Agreed that client certs can be useful for mail submission >authentication. But I was wondering about the feasibility of migrating >to use of client certificates for relay to mail exchangers, i.e. across >administrative mail domain boundaries. I don't see what problem it would solve. The only path authentication that MTAs do now is SPF, which most people agree is pretty lousy, and in the other direction IP based DNSBLs. Most certs are signed by Let's Encrypt, who promise little more than that the entity presenting the cert is the same one that presented the signing request. That doesn't impress me as any better than using an IP address. Whitelisting mail by source on the assumption that you can identify sources that send good mail is a Well Known Bad Idea. Any source big enough to be worth whitelisting is big enough to have accounts that get compromised and users infected by malware, so legit mail sources all send some spam, too. Apropos whitelisting, I can tell you long tedious stories about all the people who insisted that Spamhaus needed to publish a whitelist. When we did, we found that nobody who qualified cared if they were whitelisted, and nobody who wanted to be listed met the criteria. R's, John
- [ietf-smtp] Possible cont4ibution to moving forwa… John C Klensin
- Re: [ietf-smtp] Possible cont4ibution to moving f… Dave Crocker
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… John C Klensin
- Re: [ietf-smtp] Possible cont4ibution to moving f… John C Klensin
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Viktor Dukhovni
- Re: [ietf-smtp] Possible cont4ibution to moving f… Viktor Dukhovni
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… John C Klensin
- Re: [ietf-smtp] Possible cont4ibution to moving f… Viktor Dukhovni
- Re: [ietf-smtp] Possible cont4ibution to moving f… Jeremy Harris
- Re: [ietf-smtp] Possible cont4ibution to moving f… Alessandro Vesely
- Re: [ietf-smtp] Possible contiibution to moving f… John C Klensin
- Re: [ietf-smtp] Possible contiibution to moving f… Viktor Dukhovni
- Re: [ietf-smtp] Possible contiibution to moving f… John C Klensin
- Re: [ietf-smtp] Possible contribution to moving f… Viktor Dukhovni
- Re: [ietf-smtp] Possible contribution to moving f… John C Klensin
- Re: [ietf-smtp] Possible contribution to moving f… S Moonesamy
- Re: [ietf-smtp] Possible cont4ibution to moving f… Barry Leiba
- Re: [ietf-smtp] Possible cont4ibution to moving f… Dave Crocker
- Re: [ietf-smtp] Possible cont4ibution to moving f… John Levine
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… John Levine
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… John R Levine
- Re: [ietf-smtp] Possible cont4ibution to moving f… Laura Atkins
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Laura Atkins
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Laura Atkins
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Endless debate on IP literals John Levine
- Re: [ietf-smtp] Possible cont4ibution to moving f… Hector Santos
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Endless debate on IP literals Dave Crocker
- [ietf-smtp] It's not about IP-Literals, its about… Hector Santos
- Re: [ietf-smtp] Endless debate on IP literals John C Klensin
- Re: [ietf-smtp] Endless debate on IP literals John R Levine
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- Re: [ietf-smtp] Endless debate on IP literals Dave Crocker
- Re: [ietf-smtp] Possible cont4ibution to moving f… Jeremy Harris
- Re: [ietf-smtp] Endless debate on IP literals John R Levine
- Re: [ietf-smtp] Endless debate on IP literals Dave Crocker
- Re: [ietf-smtp] Endless debate on IP literals Dave Crocker
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- Re: [ietf-smtp] Endless debate on IP literals John R Levine
- Re: [ietf-smtp] Possible cont4ibution to moving f… John Levine
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible contribution to moving f… Viktor Dukhovni
- Re: [ietf-smtp] Possible contribution to moving f… Keith Moore
- Re: [ietf-smtp] SMTP client certs John Levine
- Re: [ietf-smtp] Endless debate on IP literals John Levine
- Re: [ietf-smtp] Possible contribution to moving f… Richard Clayton
- Re: [ietf-smtp] Possible contribution to moving f… John Levine
- Re: [ietf-smtp] Possible contribution to moving f… Viktor Dukhovni
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- Re: [ietf-smtp] Possible contribution to moving f… Keith Moore
- Re: [ietf-smtp] Endless debate on IP literals John R Levine
- Re: [ietf-smtp] Endless debate on IP literals Viktor Dukhovni
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- Re: [ietf-smtp] Endless debate on IP literals John Levine
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- Re: [ietf-smtp] Possible contribution to moving f… Dave Crocker
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- Re: [ietf-smtp] Endless debate on IP literals John Levine
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- Re: [ietf-smtp] Endless debate on IP literals Viktor Dukhovni
- Re: [ietf-smtp] Endless debate on IP literals Alessandro Vesely
- Re: [ietf-smtp] Possible contribution to moving f… Hector Santos
- Re: [ietf-smtp] Possible contribution to moving f… Hector Santos
- Re: [ietf-smtp] Endless debate on IP literals Dave Crocker
- Re: [ietf-smtp] Possible cont4ibution to moving f… Hector Santos
- Re: [ietf-smtp] Endless debate on IP literals Hector Santos
- Re: [ietf-smtp] Endless debate on IP literals John R Levine
- Re: [ietf-smtp] Possible contribution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Hector Santos
- Re: [ietf-smtp] Possible cont4ibution to moving f… Dave Crocker
- Re: [ietf-smtp] Endless debate on IP literals Dave Crocker
- Re: [ietf-smtp] Possible contribution to moving f… John C Klensin
- Re: [ietf-smtp] Possible contribution to moving f… Dave Crocker
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Dave Crocker
- Re: [ietf-smtp] Possible cont4ibution to moving f… Arnt Gulbrandsen
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- Re: [ietf-smtp] Possible contribution to moving f… Keith Moore
- Re: [ietf-smtp] Possible contribution to moving f… Dave Crocker
- Re: [ietf-smtp] Possible contribution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Dave Crocker
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Dave Crocker
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Possible contribution to moving f… John C Klensin
- Re: [ietf-smtp] Possible contribution to moving f… Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… John Levine
- Re: [ietf-smtp] Possible cont4ibution to moving f… John Levine
- Re: [ietf-smtp] Possible contribution to moving f… Dave Crocker
- Re: [ietf-smtp] Endless debate on IP literals Ned Freed
- Re: [ietf-smtp] Possible cont4ibution to moving f… Dave Crocker
- Re: [ietf-smtp] Endless debate on IP literals Ned Freed
- Re: [ietf-smtp] Endless debate on IP literals Dave Crocker
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- [ietf-smtp] lounging around Dave Crocker
- Re: [ietf-smtp] Endless debate on IP literals Keith Moore
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] Endless debate on IP literals John R Levine
- Re: [ietf-smtp] Possible cont4ibution to moving f… Keith Moore
- Re: [ietf-smtp] lounging around John Levine
- Re: [ietf-smtp] Endless debate on submission auth… John Levine
- Re: [ietf-smtp] lounging around John Levine
- Re: [ietf-smtp] lounging around Keith Moore
- Re: [ietf-smtp] lounging around Dave Crocker