The Linux kernel mailing list has a very specific format to reply to threads. This requires creating a contact for each email manually (which can be easily +5) and I don’t know if creating a contact for the in-reply-to works.
E.g.: Re: [PATCH] btrfs: include device major and minor numbers in the device scan notice - Qu Wenruo
I don’t think it’s a good idea to paste the emails here, but at the end of the page you will find the git send-email and the mailto: link.
It would be nice to have something that will automatically translate the mailto: url to another url that has every contact already configured and ready to be used in one click.