Here are the frequently asked questions about HES support for IPv6:
Does HES support IPv6?
HES currently does not support IPV6 feature.
If the mail server has IPv6 address, will it deliver the emails?
If the server is dual stack and sending mails with IPv4, mail delivery will be okay.
If the customer wants to approve/block certain IPv6 addresses in IP reputation services, will HES work on IPv6 sources?
No. This is not yet supported.
Will Mail Tracking and logs work and be displayed correctly?
HES Mail Tracking and other logs currently do not support IPv6 display.
Is it possible to modify the MX record to point to AAAA?
It is possible if we start to support IPv6 and then we will need to point to AAAA.