IPv6 Cheat Sheet
IPv6 is a lot less complicated that you think. Once you get past the hex codes and once you see that basic concepts and tools
ipv6
What is autoconfig and autodiscover, the related DNS records, that seems to be present in some email clients configurable using some control panels (e.g. Virtualmin and WHM)
Autoconfig and Autodiscover are lifesavers when it comes to email client software configuration. Up to date email clients like Thunderbird and Microsoft Outlook will query