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<p class="MsoNormal">Hello:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The S/MIME Certificate Working Group (SMCWG) of the CA/Browser Forum proposes to add a requirement for CAs issuing publicly-trusted S/MIME certificates to implement Certificate Authority Authorization (CAA) checking. Public-trust CAs have
used CAA for some time when issuing TLS certificates, and the new <a href="https://www.rfc-editor.org/rfc/rfc9495.html">
RFC 9495</a> extends CAA with a new property tag for “issuemail”. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The benefit is that domain holders will be able to specify CAs they authorize to issue certificates on their behalf separately for TLE and for S/MIME.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The current plan is to allow up to 12 months for CAs to implement CAA following publication of the amending ballot to
<a href="https://github.com/cabforum/smime/blob/main/SBR.md">the S/MIME Baseline Requirements</a>.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The SMCWG is now starting work on that amending ballot. We encourage both Certificate Issuers as well as PKI application software providers involved in issuing S/MIME certificates to become familiar with RFC 9495, and welcome feedback
on the pending requirement and implementation timeframe.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">With kind regards,<o:p></o:p></p>
<p class="MsoNormal">Stephen Davidson<o:p></o:p></p>
<p class="MsoNormal">Chair, S/MIME Certificate Working Group<span style="mso-ligatures:none"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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