1. Certified Server Validation (CSV) “ An MTA is talking to me directly. Are they OK?” D. Crocker Brandenburg InternetWorking mipassoc.org/csv 10/8/2015 6:36 AM D. Crocker Brandenburg InternetWorking mipassoc.org/csv 10/8/2015 6:36 AM MIPA

2. 2 2 D. CrockerIntroduction to CSV Email Security Functions Assess the safety of an agent TermFunctionIdentification Who does this purport to be? Authentication Is it really them? Authorization What are they allowed to do? Accreditation Is the entity giving them that permission itself recommended?

3. 3 3 MIPA D. CrockerIntroduction to CSV Choosing Who to Make Accountable Who Source of Identity ID Type Proposal Neighbor Site IP layerIP network Neighbor MTA IP layerIP Neighbor Admin SMTP EHLO DomainCSV Intermediary MTA Received headerDomain Submitter Envelope bounce address Email/Domain SPF, BATV Submitter Content senderEmail/Domain Sender-ID, DomainKeys Author Content authorEmail/DomainIIM

4. 4 4 MIPA D. CrockerIntroduction to CSV Email Path(s) Can Be Complicated MUAMSA MTA MTA MDA MUA MTA MTA MTA MTA MTA MTA MTA MTA MDA MUA Mail Agents MUA = User MSA = Submission MTA= Transfer MDA= Delivery

5. 5 5 MIPA D. CrockerIntroduction to CSV Path Registration Schemes Source assesses MTAs along the path MUA MSA MTA 1 MDA MUA MTA 3 MTA 2 Now do this for every recipient! Is MSA ok? Is MTA 1 ok? Is MTA 2 ok? Is MTA 3 ok? MSA Admin MSA MTA 1 MTA 2 MTA 3 MSA Admin MSA MTA 1 MTA 2 MTA 3 MSA admin registers authorized MTAs DNS

6. 6 6 MIPA D. CrockerIntroduction to CSV Certified Server Validation Local operator authorizes their own MTA MUA MSA MTA 1 MDA MUA MTA 3 MTA 2 MTA 1 OK? MTA 3 OK? MTA 2 OK? MSA OK? MSA Admin MSA MTA 1 Admin MTA 1 MTA 2 Admin MTA 2 MTA 3 Admin MTA 3 Register DNS

7. 7 7 MIPA D. CrockerIntroduction to CSV CSV In Operation FunctionFunctionsIdentification SMTP neighbor sends HELO domain-name Authentication HELO name in DNS lists MTA's IP address? Authorization HELO name in DNS authorizes MTA to send email? Accreditation 1) HELO name in DNS may list accreditors 2) Accreditors may list recommendation of HELO name in DNS

8. 8 8 MIPA D. CrockerIntroduction to CSV To follow-up…  Mailing list http://mipassoc.org/mailman/listinfo/ietf-clear  CSV specificationshttp://ietf.org/internet-drafts/… draft-ietf-marid-csv-intro-01  Client SMTP Validation (CSV) draft-ietf-marid-csv-intro-01 draft-ietf-marid-csv-csa-01  Client SMTP Authorization (CSA) draft-ietf-marid-csv-csa-01 draft-ietf-marid-csv-dna-01  Domain Name Accreditation (DNA) draft-ietf-marid-csv-dna-01  Internet mail architecture  draft-crocker-email-arch-01.txt  Mailing list http://mipassoc.org/mailman/listinfo/ietf-clear  CSV specificationshttp://ietf.org/internet-drafts/… draft-ietf-marid-csv-intro-01  Client SMTP Validation (CSV) draft-ietf-marid-csv-intro-01 draft-ietf-marid-csv-csa-01  Client SMTP Authorization (CSA) draft-ietf-marid-csv-csa-01 draft-ietf-marid-csv-dna-01  Domain Name Accreditation (DNA) draft-ietf-marid-csv-dna-01  Internet mail architecture  draft-crocker-email-arch-01.txt