Level3 (3356) to outlook.office365.com via v6?

[David Hubbard <dhubbard () dino hostasaurus com>]

Curious if anyone else is having issues reaching outlook.office365.com via ipv6 over Level 3?  Our customers have begun 
reporting failures checking email, and in the ones who have had this issue, are using the mail server name 
outlook.office365.com and are on v6.  Traceroute6 shows the traffic dying shortly into Level 3 land at 
2001:1900:4:1::3d1 which is likely a Tampa-area router.

Thanks,

David