<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">I’ve not experienced this problem sending emails via IPv6 to gmail destinations from my personal domain.<div class=""><br class=""></div><div class="">(<a href="http://delong.com" class="">delong.com</a>)</div><div class=""><br class=""></div><div class="">Likely this email will, in fact, get sent to GMAIL via IPv6.</div><div class=""><br class=""></div><div class="">I do have good SPF and DKIM records and signing and a reasonable DMARC policy set up.</div><div class=""><br class=""></div><div class="">If ISC doesn’t have that yet, it might be a better alternative than turning off IPv6.</div><div class=""><br class=""></div><div class="">If that doesn’t solve it, I can reach out to someone at Google who can likely get the right parties involved.</div><div class=""><br class=""></div><div class="">Owen</div><div class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Apr 2, 2022, at 15:23, Jeroen Massar via NANOG <<a href="mailto:nanog@nanog.org" class="">nanog@nanog.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">Hi Dan,<br class=""><br class="">Hope the rest of the world is treating you decently!<br class=""><br class="">There are a lot of bits and bobs that one has to get right for mail to flow, amongst which:<br class=""><br class=""> - IP -> PTR lookup -> that hostname lookup, and match to IP again<br class=""> (<a href="https://en.wikipedia.org/wiki/Forward-confirmed_reverse_DNS" class="">https://en.wikipedia.org/wiki/Forward-confirmed_reverse_DNS</a>)<br class=""> - SPF<br class=""> - DKIM<br class=""> - DMARC<br class=""> - ARC (for mailinglists)<br class=""> - SRS (When forwarding, rewrite the From and resign DKIM, and then ARC-sign that)<br class=""> - Decent TLS<br class=""> - MTA-STS<br class=""><br class="">And that list grows and grows... and grows and grows. It is kinda a test if one has actually bothered to configure a setup, and not just are randomly sending an email by just telneting from a random server. Of course the large spam outfits have this fully automated and configured, so that their spam^Wadvertising comes through.<br class=""><br class="">A wee little test tells that there are a few improvements to be made at minimum:<br class=""><br class=""><a href="https://internet.nl/mail/isc.org/" class="">https://internet.nl/mail/isc.org/</a><br class=""><br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>• Not all authenticity marks against email phishing (DMARC, DKIM and SPF)<br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>• Failed :Mail server connection not or insufficiently secured (STARTTLS and DANE)<br class=""><br class=""><br class="">Greets,<br class=""> Jeroen (who also runs his own full net... and had jeroen@isc for a few years... ;) )<br class=""><br class=""></div></div></blockquote></div><br class=""></div></body></html>