Here's a list of things I consider necessary. The list is incomplete, but I do
think that an ISP should tick at least all of these boxes in order to be proud
of their IPv6 support. Please let me know if you know of an ISP that does
already do all of this.


Internet access (regardless whether colo, DSL, VPS...):
[X] Native routable IPV6
[X] ...Available on all connections
[/] ...With automatic configuration on end-user subnets
[X] IPv4 and IPv6 dual stack allowed over the same interface
[X] Prefix /<64 available, automatically or on request

Mail:
[X] Receive SMTP-to-SMTP mail over IPv6 (MX)
[X] ...With a different secondary MX also reachable over IPv6
[X] POP3 and IMAP server reachable over IPv6
[X] ...On the same hostnames as IPv4
[X] Submission/SMTP server reachable over IPv6
[X] ...On the same hostnames as IPv4
[X] Mail servers can send mail to IPv6 hosts
[X] ...And the SPF records, if present, cover the IPv6 outbound SMTP server

DNS:
[X] Authoritative nameserver reachable over IPv6
[X] ...With a different secondary NS also reachable over IPv6
[X] AAAA glue records
[X] Support for AAAA records in authoritative zones
[X] ...Without discrimination: available for all users, even IPv4 users
[ ] ...Unique reverse DNS (PTR) records that point to forward-correct hostnames
[X] DNS cache reachable over IPv6
[ ] ...Separate server, not shared with IPv4 users (Google demands this)
[X] Support for AAAA records in recursive DNS, optionally blocked opt-in

Websites:
[X] HTTP websites are reachable over IPv6
[X] ...On the same hostnames as IPv4
[X] HTTPS websites are reachable over IPv6
[X] ...On the same hostnames as IPv4
[ ] Web services that fetch from or publish to to external URLs support IPv6